View source for Rat

{{Short description|Several genera of rodents}}
{{Other uses}}
{{Redirect|Rats|"The Rats"|The Rats (disambiguation)}}
{{pp-semi-protected|small=yes}}
{{More citations needed|date=September 2019}}
{{Paraphyletic group
| auto = yes
| name = Rats
| image = Brown Rat (Rattus norvegicus).jpg
| image_caption = [[Brown rat]] (''Rattus norvegicus'')
| parent = Rodentia
}}
'''Rats''' are various medium-sized, long-tailed [[rodent]]s. Species of rats are found throughout the order Rodentia, but stereotypical rats are found in the genus ''[[Rattus]]''. Other rat genera include ''[[Neotoma]]'' (pack rats), ''[[Bandicota]]'' (bandicoot rats) and ''[[Dipodomys]]'' (kangaroo rats).
Rats are typically distinguished from [[mouse|mice]] by their size. Usually the [[common name]] of a large [[muroid]] rodent will include the word "rat", while a smaller muroid's name will include "mouse". The common terms ''rat'' and ''mouse'' are not [[Taxonomy (biology)|taxonomically]] specific. There are 56 known species of rats in the world.<ref>{{Cite news|title=Rat Fact Sheet|url=https://www.pbs.org/wnet/nature/blog/rat-fact-sheet/|access-date=2021-09-23|newspaper=Nature|language=en}}</ref>
==<span class="anchor" id="Species"></span>Species and description<!-- This Anchor tag serves to provide a permanent target for incoming section links. Please do not remove it, nor modify it, except to add another appropriate anchor. If you modify the section title, please anchor the old title. It is always best to anchor an old section header that has been changed so that links to it will not be broken. See [[Template:Anchor]] for details. This text is produced using {{subst:Anchor comment}} -->==
[[File:Rat in a suburban Vancouver driveway.jpg|thumb|left|A rat in a [[suburb]] of [[Vancouver]]]][[File:Black Rat skeleton.jpg|thumb|Skeleton of a black rat (''[[Black rat|Rattus rattus]]'') on display at the [[Museum of Osteology]].|left]]
The best-known rat [[species]] are the [[black rat]] (''Rattus rattus'') and the [[brown rat]] (''Rattus norvegicus''). This group, generally known as the [[Old World]] rats or true rats, originated in [[Asia]]. Rats are bigger than most Old World [[mouse|mice]], which are their relatives, but seldom weigh over {{convert|500|g|oz|frac=2}} in the wild.<ref>{{cite web|url=http://www.livescience.com/28028-mice.html|title=Habits, Habitat & Types of Mice|work=Live Science|date=26 June 2014|access-date=23 May 2015|url-status=live|archive-url=https://web.archive.org/web/20150524081143/http://www.livescience.com/28028-mice.html|archive-date=24 May 2015}}</ref>
The term ''rat'' is also used in the names of other small [[mammals]] that are not true rats. Examples include the North American [[pack rats]] (aka wood rats<ref name="Britannica Concise Encyclopedia">{{Cite book|title=Britannica Concise Encyclopedia|publisher=Britannica Digital Learning|year=2017|location=Chicago, IL|via=Credo Reference}}</ref>) and a number of species loosely called [[kangaroo rats]].<ref name="Britannica Concise Encyclopedia" /> Rats such as the [[bandicoot rat]] (''Bandicota bengalensis'') are [[murine]] rodents related to true rats but are not members of the genus ''Rattus''.<ref>{{Cite web |title=Bandicota Gray, 1873 |url=https://www.gbif.org/species/2437726 |access-date=2024-03-10 |website=www.gbif.org |language=en}}</ref><ref>{{Cite web |title=ITIS - Report: Bandicota bengalensis |url=https://www.itis.gov/servlet/SingleRpt/SingleRpt?search_topic=TSN&search_value=585160#null |access-date=2024-03-10 |website=www.itis.gov}}</ref>
Male rats are called ''bucks''; unmated females, ''does'', pregnant or parent females, ''dams''; and infants, ''kittens'' or ''pups''. A group of rats is referred to as a ''mischief''.<ref>{{cite web|url=http://www.abc.net.au/creaturefeatures/facts/rats.htm|title=Creature Feature Rats|work=ABC.net.au|access-date=23 May 2015|url-status=dead|archive-url=https://web.archive.org/web/20150524080725/http://www.abc.net.au/creaturefeatures/facts/rats.htm|archive-date=24 May 2015}}</ref>
The common species are opportunistic survivors and often live with and near [[humans]]; therefore, they are known as [[commensalism|commensals]]. They may cause substantial food losses, especially in developing countries.<ref>{{cite journal |vauthors=Meerburg BG, Singleton GR, Leirs H |title=The Year of the Rat ends: time to fight hunger!|journal=Pest Manag Sci |volume=65 |issue=4 |year=2009 |pmid=19206089 |doi=10.1002/ps.1718 |url=http://www3.interscience.wiley.com/journal/121686000/abstract |archive-url=https://archive.today/20121217192631/http://www3.interscience.wiley.com/journal/121686000/abstract |url-status=dead |archive-date=2012-12-17 |pages=351–2}}</ref> However, the widely distributed and problematic commensal species of rats are a minority in this diverse genus. Many species of rats are [[Endemic (ecology)|island endemics]], some of which have become [[endangered species|endangered]] due to habitat loss or competition with the brown, black, or [[Polynesian rat]].<ref>{{cite journal|title=Competition in an invaded rodent community reveals black rats as a threat to native bush rats in littoral rainforest of south-eastern Australia|journal= Journal of Applied Ecology|volume=46|issue=6|pages=1239–1247|doi=10.1111/j.1365-2664.2009.01735.x|year=2009|last1=Stokes|first1=Vicki L.|last2=Banks|first2=Peter B.|last3=Pech|first3=Roger P.|last4=Spratt|first4=David M.|bibcode= 2009JApEc..46.1239S|doi-access=free}}</ref>
Wild rodents, including rats, can carry many different [[zoonotic]] pathogens, such as ''[[Leptospira]]'', ''[[Toxoplasma gondii]]'', and ''[[Campylobacter]]''.<ref name="Meerburg BG, Singleton GR, Kijlstra A 2009">{{cite journal |vauthors=Meerburg BG, Singleton GR, Kijlstra A |title=Rodent-borne diseases and their risks for public health|journal=Crit Rev Microbiol|volume=35 |issue=3|year=2009 |pmid=19548807|doi=10.1080/10408410902989837|pages=221–70|s2cid=205694138}}</ref> The [[Black Death]] is traditionally believed to have been caused by the microorganism ''[[Yersinia pestis]]'', carried by the tropical rat flea (''[[Xenopsylla cheopis]]''), which preyed on black rats living in European cities during the epidemic outbreaks of the [[Middle Ages]]; these rats were used as transport hosts. Another zoonotic disease linked to the rat is [[foot-and-mouth disease]].<ref>{{cite journal |last=Capel-Edwards |first=Maureen |title=Foot-and-mouth disease in the brown rat |date=October 1970 |journal=Journal of Comparative Pathology |volume=80 |issue=4 |pages=543–548 |doi=10.1016/0021-9975(70)90051-4|pmid=4321688 }}</ref>
Rats become sexually mature at age 6 weeks, but reach social maturity at about 5 to 6 months of age. The average lifespan of rats varies by species, but many only live about a year due to predation.<ref>{{cite web|url=http://www.ratbehavior.org/RatYears.htm|title=How old is a rat in human years?|work=RatBehavior.org|access-date=23 May 2015|url-status=live|archive-url=https://web.archive.org/web/20150612010521/http://www.ratbehavior.org/RatYears.htm|archive-date=12 June 2015}}</ref>
The black and brown rats diverged from other [[Murinae|Old World rats]] in the forests of Asia during the beginning of the [[Pleistocene]].<ref>{{cite journal |last1=Aplin |first1=Ken P. |last2=Suzuki |first2=Hitoshi |last3=Chinen |first3=Alejandro A. |last4=Chesser |first4=R. Terry |last5=ten Have |first5=José |last6=Donnellan |first6=Stephen C. |last7=Austin |first7=Jeremy |last8=Frost |first8=Angela |last9=Gonzalez |first9=Jean Paul |last10=Herbreteau |first10=Vincent |last11=Catzeflis |first11=Francois |last12=Soubrier |first12=Julien |last13=Fang |first13=Yin-Ping |last14=Robins |first14=Judith |last15=Matisoo-Smith |first15=Elizabeth |last16=Bastos |first16=Amanda D. S. |last17=Maryanto |first17=Ibnu |last18=Sinaga |first18=Martua H. |last19=Denys |first19=Christiane |last20=Van Den Bussche |first20=Ronald A. |last21=Conroy |first21=Chris |last22=Rowe |first22=Kevin |last23=Cooper |first23=Alan |display-authors=6 |title=Multiple Geographic Origins of Commensalism and Complex Dispersal History of Black Rats |date=November 2011 |journal=PLOS ONE |volume=6 |number=11 |page=e26357 |doi=10.1371/journal.pone.0026357 |pmid=22073158 |pmc=3206810 |bibcode=2011PLoSO...626357A |doi-access=free }}</ref>
==Rat tails==
[[File:Ratt tail detail.jpg|thumb|A closeup of a rat tail]]
The characteristic long tail of most rodents is a feature that has been extensively studied in various rat species models, which suggest three primary functions of this structure: [[thermoregulation]],<ref>{{cite web |title=Rat Tails |url=http://www.ratbehavior.org/RatTails.htm |website=Rat Behavior and Biology |access-date=30 July 2020}}</ref> minor [[proprioception]], and a [[nocifensive]]-mediated [[degloving]] response.<ref>{{cite web |last1=Grant |first1=Karen |title=Degloving Injury |url=http://ratguide.com/health/trauma/degloving_injury.php |website=Rat Health Guide |access-date=30 July 2020}}</ref> Rodent tails—particularly in rat models—have been implicated with a thermoregulation function that follows from its anatomical construction. This particular tail morphology is evident across the family Muridae, in contrast to the bushier tails of [[Squirrel|Sciuridae]], the squirrel family. The tail is hairless and thin skinned but highly vascularized, thus allowing for efficient [[countercurrent heat exchange]] with the environment. The high [[Muscular tissue|muscular]] and [[connective tissue]] densities of the tail, along with ample muscle attachment sites along its plentiful [[caudal vertebrae]], facilitate specific proprioceptive senses to help orient the rodent in a three-dimensional environment.<ref>{{cite journal | vauthors=Vincent JA, Gabriel HM, Deardorff AS, Nardelli P, Fyffe RE, Burkholder T, Cope TC | journal=Journal of Neurophysiology | title=Muscle proprioceptors in adult rat: mechanosensory signaling and synapse distribution in spinal cord | volume=118 | issue=5 | pages=2687–2701 | date=1 November 2017 | issn=0022-3077 | doi=10.1152/jn.00497.2017 | pmid=28814636 | pmc=5672542 }}</ref> Murids have evolved a unique defense mechanism termed ''degloving'' that allows for escape from predation through the loss of the outermost [[integument]]ary layer on the tail. However, this mechanism is associated with multiple [[pathologies]] that have been the subject of investigation.{{citation needed|date=December 2018}}
[[File:Murid Tail Microscopy Cross Section.jpg|thumb|219x219px|Microscopic cross section of ''Rattus rattus'' tail, delineating tendon bundles, vasculature, and vertebral canal.]]
Multiple studies have explored the thermoregulatory capacity of rodent tails by subjecting test organisms to varying levels of physical activity and quantifying [[Thermal conduction|heat conduction]] via the animals' tails. One study demonstrated a significant disparity in [[heat dissipation]] from a rat's tail relative to its abdomen.<ref>{{Cite journal|last=Wanner|first=Samuel|date=2015|title=Thermoregulatory responses in exercising rats: methodological aspects and relevance to human physiology|journal=Temperature|volume=2|issue=4|pages=457–75|doi=10.1080/23328940.2015.1119615|pmid=27227066|pmc=4844073}}</ref> This observation was attributed to the higher proportion of [[vascularity]] in the tail, as well as its higher [[surface-area-to-volume ratio]], which directly relates to heat's ability to dissipate via the skin. These findings were confirmed in a separate study analyzing the relationships of heat storage and [[mechanical efficiency]] in rodents that exercise in warm environments. In this study, the tail was a focal point in measuring heat accumulation and modulation.{{citation needed|date=December 2018}}
On the other hand, the tail's ability to function as a proprioceptive sensor and modulator has also been investigated. As aforementioned, the tail demonstrates a high degree of muscularization and subsequent [[innervation]] that ostensibly collaborate in orienting the organism.<ref>{{Cite journal|last=Mackenzie|first=SJ|date=2015|title=Innervation and function of rat tail muscles for modeling cauda equina injury and repair.|journal=Muscle and Nerve|volume=52|issue=1|pages=94–102|doi=10.1002/mus.24498|pmid=25346299|s2cid=40356618}}</ref> Specifically, this is accomplished by coordinated [[flexion]] and extension of tail muscles to produce slight shifts in the organism's [[center of mass]], orientation, etc., which ultimately assists it with achieving a state of proprioceptive balance in its environment. Further mechanobiological investigations of the constituent [[tendon]]s in the tail of the rat have identified multiple factors that influence how the organism navigates its environment with this structure. A particular example is that of a study in which the morphology of these tendons is explicated in detail.<ref>{{Cite journal|last=Bruneau|first=Amelia|date=2010|title=Preparation of Rat Tail Tendons for Biomechanical and Mechanobiological Studies|journal=Journal of Visualized Experiments|volume=41|issue=41|pages=2176|pmc=3156064|pmid=20729800|doi=10.3791/2176}}</ref> Namely, [[Viability assay|cell viability tests]] of tendons of the rat's tail demonstrate a higher proportion of living [[fibroblast]]s that produce the [[collagen]] for these fibers. As in humans, these tendons contain a high density of [[golgi tendon organ]]s that help the animal assess stretching of muscle [[in situ]] and adjust accordingly by relaying the information to higher [[Cerebral cortex|cortical]] areas associated with balance, proprioception, and movement.{{Citation needed|date=December 2018}}
The characteristic tail of murids also displays a unique defense mechanism known as ''[[degloving]]'' in which the outer layer of the integument can be detached in order to facilitate the animal's escape from a predator. This evolutionary selective pressure has persisted despite a multitude of [[pathologies]] that can manifest upon [[Shedding (biology)|shedding]] part of the tail and exposing more interior elements to the environment.<ref>{{Cite journal|last=Milcheski|first=Dimas|date=2012|title=Development of an experimental model of degloving injury in rats|journal=Brazilian Journal of Plastic Surgery|volume=27|pages=514–17}}</ref> Paramount among these are [[bacteria]]l and [[Virus|viral]] infection, as the high density of [[vascular tissue]] within the tail becomes exposed upon [[Avulsion injury|avulsion]] or similar injury to the structure. The degloving response is a [[wikt:nocifensive|nocifensive]] response, meaning that it occurs when the animal is subjected to [[acute pain]], such as when a predator snatches the organism by the tail.{{citation needed|date=December 2018}}
==As pets==
{{anchor|Pets}}
{{main|Fancy rat}}
[[File:Rat shoulder.jpg|thumb|upright|A [[domesticated]] rat]]
Specially bred rats have been kept as pets at least since the late 19th century. Pet rats are typically variants of the species [[brown rat]], but [[black rat]]s and [[giant pouched rat]]s are also sometimes kept. Pet rats behave differently from their wild counterparts depending on how many generations they have been kept as pets.<ref name=NaturalSelection>{{cite web|url=http://www.ratbehavior.org/WildAndDomesticRats.htm|title=Wild Rats in Captivity and Domestic Rats in the Wild|publisher=Ratbehaviour.org|access-date=2009-07-04|url-status=live|archive-url=https://web.archive.org/web/20090413073723/http://www.ratbehavior.org/WildAndDomesticRats.htm|archive-date=2009-04-13}}</ref> Pet rats do not pose any more of a risk of [[zoonotic disease]]s than pets such as [[cat]]s or [[dog]]s.<ref name=Zoonoses>{{cite web|url=http://www.merckvetmanual.com/mvm/htm/bc/tzns01.htm|title=Merk Veterinary Manual Global Zoonoses Table|publisher=Merckvetmanual.com|access-date=2006-11-24|url-status=dead|archive-url=https://web.archive.org/web/20070217135931/http://www.merckvetmanual.com/mvm/htm/bc/tzns01.htm|archive-date=2007-02-17}}</ref> Tamed rats are generally friendly and can be taught to perform selected behaviors.
Selective breeding has brought about different color and marking varieties in rats. Genetic mutations have also created different fur types, such as rex and hairless. Congenital malformation in selective breeding have created the dumbo rat, a popular pet choice due to their low, saucer-shaped ears.<ref name="DumboCongenital">{{cite journal |last1=Katerji |first1=Suhair |title=Expression of Msx1 and Dlx1 during Dumbo rat head development: correlation with morphological features |journal=Genetics and Molecular Biology |date=1 May 2009 |volume=32 |issue=2 |pages=399–404 |doi=10.1590/S1415-47572009005000041 |pmid=21637698 |pmc=3036941 |doi-access=free }}</ref> A breeding standard exists for rat fanciers wishing to breed and show their rat at a rat show.<ref name="afrmastandard">{{cite web |title=AFRMA OFFICIAL RAT STANDARD |url=https://www.afrma.org/stdsrat.htm |publisher=American Fancy Rat & Mouse Association |access-date=13 October 2020}}</ref>
==As subjects for scientific research==
{{Anchor|Subjects for scientific research}}
{{main|Laboratory rat}}
[[File:Rat diabetic.jpg|thumb|left|A laboratory rat strain, known as a [[Zucker rat]], bred to be genetically prone to [[Diabetes mellitus|diabetes]], a [[metabolic disorder]] also found among humans.]]
In 1895, [[Clark University]] in [[Worcester, Massachusetts]], established a population of domestic [[albino]] brown rats to study the effects of diet and for other [[physiology|physiological]] studies.<ref>{{Cite web |title=Rat - an overview {{!}} ScienceDirect Topics |url=https://www.sciencedirect.com/topics/veterinary-science-and-veterinary-medicine/rat |access-date=2024-04-09 |website=www.sciencedirect.com}}</ref> Over the years, rats have been used in many experimental studies, adding to our understanding of [[genetics]], [[disease]]s, the effects of [[drug]]s, and other topics that have provided a great benefit for the [[health]] and wellbeing of humankind.<ref>{{Citation |last=Research |first=National Research Council (US) and Institute of Medicine (US) Committee on the Use of Laboratory Animals in Biomedical and Behavioral |title=Benefits Derived from the Use of Animals |date=1988 |work=Use of Laboratory Animals in Biomedical and Behavioral Research |url=https://www.ncbi.nlm.nih.gov/books/NBK218274/ |access-date=2024-04-09 |publisher=National Academies Press (US) |language=en}}</ref>
The [[aortic arch]]es of the rat are among the most commonly studied in murine models due to marked [[comparative anatomy|anatomical homology]] to the human [[cardiovascular system]].<ref name=":0">{{Cite journal|last1=Casteleyn|first1=Christophe|last2=Trachet|first2=Bram|last3=Van Loo|first3=Denis|last4=Devos|first4=Daniel G H|last5=Van den Broeck|first5=Wim|last6=Simoens|first6=Paul|last7=Cornillie|first7=Pieter|date=2017-04-19|title=Validation of the murine aortic arch as a model to study human vascular diseases|journal=Journal of Anatomy|volume=216|issue=5|pages=563–571|doi=10.1111/j.1469-7580.2010.01220.x|issn=0021-8782|pmc=2871992|pmid=20345858}}</ref> Both rat and human aortic arches exhibit subsequent branching of the [[brachiocephalic trunk]], left [[common carotid artery]], and left [[subclavian artery]], as well as geometrically similar, nonplanar curvature in the [[Aorta#Aortic arch|aortic branch]]es.<ref name=":0" /> Aortic arches studied in rats exhibit abnormalities similar to those of humans, including altered [[pulmonary arteries]] and double or absent aortic arches.<ref>{{Cite journal|last1=Wilson|first1=James G.|last2=Warkany|first2=Josef|date=1950-04-01|title=Cardiac and Aortic Arch Anomalies in the Offspring of Vitamin a Deficient Rats Correlated with Similar Human Anomalies|url=http://pediatrics.aappublications.org/content/5/4/708|journal=Pediatrics|language=en|volume=5|issue=4|pages=708–725|doi=10.1542/peds.5.4.708|issn=0031-4005|pmid=15417271|s2cid=46479766|url-status=live|archive-url=https://web.archive.org/web/20170818222732/http://pediatrics.aappublications.org/content/5/4/708|archive-date=2017-08-18}}</ref> Despite existing anatomical analogy in the inthrathoracic position of the heart itself, the murine model of the heart and its structures remains a valuable tool for studies of human cardiovascular conditions.<ref>{{Cite journal|last1=Casteleyn|first1=Christophe|last2=Trachet|first2=Bram|last3=Van Loo|first3=Denis|last4=Devos|first4=Daniel G H|last5=Van den Broeck|first5=Wim|last6=Simoens|first6=Paul|last7=Cornillie|first7=Pieter|date=2017-04-27|title=Validation of the murine aortic arch as a model to study human vascular diseases|journal=Journal of Anatomy|volume=216|issue=5|pages=563–571|doi=10.1111/j.1469-7580.2010.01220.x|issn=0021-8782|pmc=2871992|pmid=20345858}}</ref>
The rat's larynx has been used in experimentations that involve inhalation toxicity, allograft rejection, and irradiation responses. One experiment described four features of the rat's larynx. The first being the location and attachments of the thyroarytenoid muscle, the alar cricoarytenoid muscle, and the superior cricoarytenoid muscle, the other of the newly named muscle that ran from the arytenoid to a midline tubercle on the cricoid. The newly named muscles were not seen in the human larynx. In addition, the location and configuration of the laryngeal alar cartilage was described. The second feature was that the way the newly named muscles appear to be familiar to those in the human larynx. The third feature was that a clear understanding of how MEPs are distributed in each of the laryngeal muscles was helpful in understanding the effects of botulinum toxin injection. The MEPs in the posterior cricoarytenoid muscle, lateral cricoarytenoid muscle, cricothyroid muscle, and superior cricoarytenoid muscle were focused mostly at the midbelly. In addition, the medial thyroarytenoid muscle were focused at the midbelly while the lateral thyroarytenoid muscle MEPs were focused at the anterior third of the belly. The fourth and final feature that was cleared up was how the MEPs were distributed in the thyroarytenoid muscle.<ref>{{cite journal |last1=Inagi |first1=Katsuhide |last2=Schultz |first2=Edward |last3=Ford |first3=Charles |title=An Anatomic Study of the Rat Larynx: Establishing the Rat Model for Neuromuscular Function |journal=Otolaryngology–Head and Neck Surgery |date=1998 |volume=118 |issue=1 |pages=74–81 |doi=10.1016/s0194-5998(98)70378-x|pmid=9450832 |s2cid=30325002 }}</ref>
Laboratory rats have also proved valuable in psychological studies of learning and other mental processes (Barnett 2002), as well as to understand [[group behavior]] and overcrowding (with the work of [[John B. Calhoun]] on [[behavioral sink]]).<ref>{{Cite web |title=Why do we use rats? |url=https://www.cam.ac.uk/research/research-at-cambridge/animal-research/what-types-of-animal-do-we-use/rats#:~:text=Almost%20all%20disease%2Dlinked%20human,less%20timid%20and%20more%20intelligent. |access-date=April 9, 2024 |website=Cambridge University| date=28 October 2016 }}</ref><ref>{{Cite web |last1=Ramsden |first1=Edmund |last2=Adams |first2=Jon |date=January 2008 |title=Escaping the Laboratory: The Rodent Experiments of John B. Calhoun & Their Cultural Influence |url=https://eprints.lse.ac.uk/22514/1/2308Ramadams.pdf |access-date=April 9, 2024 |website=Department of Economic History at London School of Economics}}</ref> A 2007 study found rats to possess [[metacognition]], a mental ability previously only documented in humans and some [[primates]].<ref>{{cite journal|last=Foote|first=Allison L.|author2=Jonathon D. Crystal|title=Metacognition in the rat|journal=Current Biology|volume=17|issue=6|pages=551–555|date=20 March 2007|url=http://www.current-biology.com/content/article/abstract?uid=PIIS0960982207009311|archive-url=https://archive.today/20120703135956/http://www.current-biology.com/content/article/abstract?uid=PIIS0960982207009311|url-status=dead|archive-date=3 July 2012|doi=10.1016/j.cub.2007.01.061|pmid=17346969|pmc=1861845|bibcode=2007CBio...17..551F }}</ref><ref>{{cite web |url=https://www.sciencedaily.com/releases/2007/03/070308121856.htm |title=Rats Capable Of Reflecting On Mental Processes |publisher=Sciencedaily.com |date=2007-03-09 |access-date=2012-09-24 |url-status=live |archive-url=https://web.archive.org/web/20121010181954/https://www.sciencedaily.com/releases/2007/03/070308121856.htm |archive-date=2012-10-10 }}</ref>
Domestic rats differ from wild rats in many ways. They are calmer and less likely to bite; they can tolerate greater crowding; they breed earlier and produce more offspring; and their [[brain]]s, [[liver]]s, [[kidney]]s, [[adrenal gland]]s, and [[heart]]s are smaller (Barnett 2002).
[[Brown rat]]s are often used as [[model organism]]s for scientific research. Since the publication of the rat [[genome]] sequence,<ref>Gibbs RA et al.: Genome sequence of the Brown Norway rat yields insights into mammalian evolution.: Nature. 2004 April 1; 428(6982):475–6.</ref> and other advances, such as the creation of a rat [[SNP genotyping|SNP chip]], and the production of [[knockout rats]], the [[laboratory rat]] has become a useful genetic tool, although not as popular as [[mice]]. Entirely new [[breed]]s or "lines" of brown rats, such as the [[Wistar rat]], have been bred for use in laboratories. Much of the genome of ''Rattus norvegicus'' has been sequenced.<ref>{{cite web |title=Genome project |url=http://www.ensembl.org/Rattus_norvegicus/index.html |url-status=live |archive-url=https://web.archive.org/web/20060426133936/http://www.ensembl.org/Rattus_norvegicus/index.html |archive-date=26 April 2006 |access-date=17 February 2007 |publisher=www.ensembl.org}}</ref>
When it comes to conducting tests related to [[intelligence]], learning, and [[drug abuse]], rats are a popular choice due to their high intelligence, ingenuity, [[aggressiveness]], and [[adaptability]]. Their [[psychology]] seems in many ways similar to that of humans.<ref>{{Cite web |date=January 2017 |title=Animal studies in psychology |url=https://www.apa.org/ed/precollege/psn/2017/01/animal-studies |access-date=April 9, 2024 |website=American Psychological Association}}</ref> Inspired by [[B.F. Skinner]]’s famous box which dispensed food pellets when rats pushed a lever, photographer Augustin Lignier gave two rats periodic, unpredictable rewards for pressing a button. He likened their repeated button-pressing behaviors to people’s fascinations with digital and social media.<ref name="i735">{{cite web |last=Anthes |first=Emily |date=2024-01-23 |title=Even Rats Are Taking Selfies Now (and Enjoying It) |url=https://www.nytimes.com/2024/01/23/science/photography-rats-selfies.html |access-date=2024-11-19 |website=The New York Times}}</ref>
===General intelligence===
<!-- This header is linked in [[Intelligence]], [[Mammal]], [[Animal cognition]], and [[Neuroscience and intelligence]]; if renamed, please update links! -->
Early studies found evidence both for and against measurable intelligence using the [[g factor (psychometrics)|"g factor"]] in rats.<ref>Lashley, K., ''Brain Mechanisms and Intelligence'', Dover Publications, New York, 1929/1963, 186 pp.</ref><ref>{{cite journal | last1 = Thorndike | first1 = R | year = 1935 | title = Organization of behavior in the albino rat | journal = Genet. Psychol. Monogr | volume = 17 | pages = 1–70 }}</ref> Part of the difficulty of understanding [[animal cognition]], generally, is determining what to measure.<ref name=Matzel2017>{{cite journal |last1=Matzel |first1=LD |last2=Sauce |first2=B |title=Individual differences: Case studies of rodent and primate intelligence. |journal=Journal of Experimental Psychology: Animal Learning and Cognition |date=October 2017 |volume=43 |issue=4 |pages=325–340 |doi=10.1037/xan0000152 |pmid=28981308 |pmc=5646700}}</ref> One aspect of intelligence is the ability to learn, which can be measured using a maze like the [[T-maze]].<ref name=Matzel2017/> Experiments done in the 1920s showed that some rats performed better than others in maze tests, and if these rats were selectively bred, their offspring also performed better, suggesting that in rats an ability to learn was heritable in some way.<ref name=Matzel2017/>
==As food==
{{Main|Rat meat}}
Rat meat is a food that, while [[taboo food and drink|taboo]] in some cultures, is a dietary staple in others.<ref>{{cite web |author=Newvision Archive |url=http://www.newvision.co.ug/D/9/38/422540 |title=Rats for dinner, a delicacy to some, a taboo to many |publisher=Newvision.co.ug |date=2005-03-10 |access-date=2012-09-24 |url-status=dead |archive-url=https://web.archive.org/web/20120922012421/http://www.newvision.co.ug/D/9/38/422540 |archive-date=2012-09-22 }}</ref>
==Working rats==
{{main|Working rat}}
{{anchor|Odor detection}}
Rats have been used as working animals. Tasks for working rats include the sniffing of gunpowder residue, [[demining]], acting and [[animal-assisted therapy]]. Rats have a keen sense of smell and are easy to train. These characteristics have been employed, for example, by the Belgian [[non-governmental organization]] [[APOPO]], which trains rats (specifically [[Gambian pouched rat|African giant pouched rats]]) to detect [[landmine]]s and diagnose [[tuberculosis]] through smell.<ref name="Ted.com">{{cite web|url=http://www.ted.com/talks/bart_weetjens_how_i_taught_rats_to_sniff_out_land_mines.html|title=Video of Bart Weetjens talk on use of rats as odour detectors|publisher=Ted.com|access-date=2012-09-24|url-status=live|archive-url=https://web.archive.org/web/20121007002748/http://www.ted.com/talks/bart_weetjens_how_i_taught_rats_to_sniff_out_land_mines.html|archive-date=2012-10-07}}</ref>
==As pests==
{{anchor|Rats as pests}}
[[File:Rodent Bait Station, Chennai, India.jpg|thumb|Rodent Bait Station, [[Chennai]], India]]
Rats have long been considered deadly pests. Once considered a modern myth, the [[mautam|rat flood]] in India occurs every fifty years, as armies of [[bamboo rat]]s descend upon rural areas and devour everything in their path.<ref>{{cite web |url=http://io9.com/5694107/massive-plagues-of-rats-swarm-across-india-every-fifty-years |title=Massive plagues of rats swarm across India every fifty years |date=19 November 2010 |publisher=Io9.com |access-date=2013-03-15 |url-status=live |archive-url=https://web.archive.org/web/20130521030122/http://io9.com/5694107/massive-plagues-of-rats-swarm-across-india-every-fifty-years |archive-date=2013-05-21 }}</ref> Rats have long been held up as the chief villain in the spread of the [[Bubonic Plague]];<ref>{{cite web |url=http://www.unc.edu/~omlor/index_files/Page393.html |title=The Black Plague |publisher=University of North Carolina |access-date=2013-03-15 |url-status=live |archive-url=https://web.archive.org/web/20130301121307/http://www.unc.edu/~omlor/index_files/Page393.html |archive-date=2013-03-01 }}</ref> however, recent studies show that rats alone could not account for the rapid spread of the disease through Europe in the [[Middle Ages]].<ref>{{cite news |author=Maev Kennedy |url=https://www.theguardian.com/world/2011/aug/17/black-death-rats-off-hook |title=Black Death study lets rats off the hook |work=The Guardian |access-date=2013-03-15 |location=London |date=2011-08-17 |url-status=live |archive-url=https://web.archive.org/web/20130827191239/http://www.theguardian.com/world/2011/aug/17/black-death-rats-off-hook |archive-date=2013-08-27 }}</ref> Still, the [[Centers for Disease Control]] does list nearly a dozen diseases<ref>{{cite web |url=https://www.cdc.gov/rodents/diseases/direct.html |title=CDC – Diseases directly transmitted by rodents – Rodents |publisher=Centers for Disease Control |date=2011-06-07 |access-date=2013-03-15 |url-status=live |archive-url=https://web.archive.org/web/20130317033523/http://www.cdc.gov/rodents/diseases/direct.html |archive-date=2013-03-17 }}</ref> directly linked to rats.
Most urban areas battle rat infestations. A 2015 study by the [[American Housing Survey]] (AHS) found that eighteen percent of homes in Philadelphia showed evidence of rodents. [[Boston]], [[New York City]], and [[Washington, D.C.]], also demonstrated significant rodent infestations.<ref>{{cite news |last=Clark |first=Patrick |url=https://www.bloomberg.com/features/2017-america-roach-rats-infected-cities/ |title=The Most Vermin-Infested American Cities |publisher=Bloomberg |date=2017-01-17 |access-date=2017-01-18 |url-status=live |archive-url=https://web.archive.org/web/20170118002206/https://www.bloomberg.com/features/2017-america-roach-rats-infected-cities/ |archive-date=2017-01-18 }}</ref> Indeed, [[rats in New York City]] are famous for their size and prevalence. The urban legend that the rat population in [[Manhattan]] equals that of its human population was definitively refuted by Robert Sullivan in his book ''Rats'' but illustrates New Yorkers' awareness of the presence, and on occasion boldness and cleverness, of the rodents.<ref>{{cite news |url=http://www.lrb.co.uk/v27/n06/sean-wilsey/some-of-them-can-read |title=Sean Wilsey reviews 'Rats' by Robert Sullivan · LRB 17 March 2005 |pages=9–10 |publisher=Lrb.co.uk |access-date=2013-03-15 |url-status=live |archive-url=https://web.archive.org/web/20130209160722/http://www.lrb.co.uk/v27/n06/sean-wilsey/some-of-them-can-read |archive-date=9 February 2013 |newspaper=London Review of Books |date=2005-03-17 |last1=Wilsey |first1=Sean}}</ref> New York has specific regulations for eradicating rats; multifamily residences and commercial businesses must use a specially trained and licensed [[rat catcher]].<ref>{{cite web |url=http://www.dec.ny.gov/chemical/8532.html |title=Questions and Answers Regarding New York State Pest Management Program |publisher=DOEC of NY State |access-date=2014-11-24 |url-status=live |archive-url=https://web.archive.org/web/20141217185555/http://www.dec.ny.gov/chemical/8532.html |archive-date=2014-12-17 }}</ref>
Chicago was declared the "rattiest city" in the US by the pest control company [[Orkin]] in 2020, for the sixth consecutive time. It's followed by [[Los Angeles]], New York, Washington, DC, and [[San Francisco]].<ref>{{cite web |title=Rats! Chicago Tops Orkin's Rattiest Cities List for Sixth Consecutive Time |url=https://www.prnewswire.com/news-releases/rats-chicago-tops-orkins-rattiest-cities-list-for-sixth-consecutive-time-301150702.html |website=PR Newswire |access-date=16 May 2021 |date=13 Oct 2020}}</ref> To help combat the problem, a Chicago animal shelter has placed more than 1000 feral cats (sterilized and vaccinated) outside of homes and businesses since 2012, where they hunt and catch rats while also providing a deterrent simply by their presence.<ref>{{cite news |last1=Guzman |first1=Joseph |title=1,000 feral cats released onto Chicago streets to tackle rat explosion |url=https://thehill.com/changing-america/sustainability/environment/552911-1000-feral-cats-released-onto-chicago-streets-to |access-date=16 May 2021 |work=The Hill |date=11 May 2021}}</ref>
Rats have the ability to swim up sewer pipes into toilets.<ref>{{cite web|title=How to keep the rats from coming up through your toilet|url=http://mynorthwest.com/11/2625820/How-to-keep-the-rats-from-coming-up-through-your-toilet|access-date=2015-08-23|first=Stephanie|last=Klein|url-status=live |archive-url=https://web.archive.org/web/20150901113140/http://mynorthwest.com/11/2625820/How-to-keep-the-rats-from-coming-up-through-your-toilet|archive-date=2015-09-01|date=2014-10-17}}</ref><ref>{{cite web|title=See How Easily a Rat Can Wriggle Up Your Toilet|url=http://video.nationalgeographic.com/video/news/150811-rats-toilet-swimming-vin|website=video.nationalgeographic.com|access-date=2015-08-23|url-status=dead |archive-url=https://web.archive.org/web/20150821025708/http://video.nationalgeographic.com/video/news/150811-rats-toilet-swimming-vin|archive-date=2015-08-21}}</ref> Rats will infest any area that provides shelter and easy access to sources of food and water, including under sinks, near garbage, and inside walls or cabinets.<ref>{{cite web | url=https://www.epa.gov/rodenticides/identify-and-prevent-rodent-infestations | title=Identify and Prevent Rodent Infestations | website =epa.gov | date=2013-10-31 | publisher =United States Environmental Protection Agency | access-date =2019-12-05}}</ref>
===In the spread of disease===
{{anchor|Medicine}}
Rats can serve as [[zoonotic]] vectors for certain pathogens and thus spread disease, such as [[bubonic plague]], [[Lassa fever]], [[leptospirosis]], and [[Hantavirus]] infection.<ref>{{Cite news|url=http://www.leptospirosis.org/other-diseases|title=Information on other rodent-related diseases – Leptospirosis Information|newspaper=Leptospirosis Information|language=en-US|access-date=2016-10-31|url-status=live|archive-url=https://web.archive.org/web/20161031152822/http://www.leptospirosis.org/other-diseases|archive-date=2016-10-31}}</ref> Researchers studying [[New York City]] wastewater have also cited rats as the potential source of "cryptic" [[Severe acute respiratory syndrome coronavirus 2|SARS-CoV-2]] lineages, due to unknown viral RNA fragments in sewage matching mutations previously shown to make SARS-CoV-2 more adept at rodent-based transmission.<ref>{{cite news |last1=Mench |first1=Chris |title=New York City's Rats Could Have Their Own Strain of COVID-19 |url=https://www.thrillist.com/news/new-york/nyc-rats-developed-their-own-covid-strain |access-date=8 February 2022 |publisher=Thrillist |date=4 February 2022 |archive-url=https://web.archive.org/web/20220205154749/https://www.thrillist.com/news/new-york/nyc-rats-developed-their-own-covid-strain |archive-date=5 February 2022}}</ref>
Rats are also associated with human [[dermatitis]] because they are frequently infested with blood feeding rodent mites such as the tropical rat mite (''[[Ornithonyssus bacoti]]'') and spiny rat mite (''Laelaps echidnina''), which will opportunistically bite and feed on humans,<ref>Watson, J. (2008). New building, old parasite: Mesostigmatid mites—an ever-present threat to barrier rodent facilities. ''ILAR journal'', ''49''(3), 303–309.</ref> where the condition is known as [[rat mite dermatitis]]''.''<ref>{{Cite journal|last1=Engel|first1=Peter M.|last2=Welzel|first2=J.|last3=Maass|first3=M.|last4=Schramm|first4=U.|last5=Wolff|first5=H. H.|date=1998|title=Tropical Rat Mite Dermatitis: Case Report and Review|journal=Clinical Infectious Diseases|language=en|volume=27|issue=6|pages=1465–1469|doi=10.1086/515016|pmid=9868661|issn=1058-4838|doi-access=free}}</ref>
==As invasive species==
{{anchor| Rats as invasive species}}
[[File:Rat catching etching E Landseer SLNSW.jpg|thumb|Rat-catching, 1823, by [[Edwin Landseer]], engraving, published by Hurst, Robinson & Co.]]
When introduced into locations where rats previously did not exist, they can wreak an enormous degree of [[environmental degradation]]. ''[[Rattus rattus]]'', the '''black rat''', is considered to be one of the world's worst invasive species.<ref>{{cite web |url=http://www.issg.org/database/species/search.asp?st=100ss&fr=1&str=&lang=EN |title=100 of the World's Worst Invasive Alien Species |publisher=Global Invasive Species Database |access-date=17 February 2013 |url-status=live |archive-url=https://web.archive.org/web/20130227061611/http://www.issg.org/database/species/search.asp?st=100ss&fr=1&str=&lang=EN |archive-date=27 February 2013 }}</ref> Also known as the '''ship rat''', it has been carried worldwide as a [[stowaway]] on [[ship|seagoing vessels]] for millennia and has usually accompanied men to any new area visited or settled by human beings by sea. Rats first got to countries such as America and Australia by stowing away on ships.<ref>{{cite web |url=https://www.dcceew.gov.au/sites/default/files/env/pages/e864dda5-e6ab-44b8-bd62-c282f61aa457/files/island-rats.pdf |title=Predation by exotic rats on Australian offshore islands of less than 1000 km2 (100,000 ha) listing advice |publisher=Government of Australia |access-date=16 February 2023}}</ref> The similar species ''[[Rattus norvegicus]]'', the '''brown rat''' or '''wharf rat''', has also been carried worldwide by ships in recent centuries.<ref>{{Cite web |title=Species – Brown Rat |url=https://www.mammal.org.uk/species-hub/full-species-hub/discover-mammals/species-brown-rat/ |access-date=2024-03-10 |website=The Mammal Society |language=en-GB}}</ref>
The ship or wharf rat has contributed to the extinction of many species of wildlife, including birds, small mammals, reptiles, invertebrates, and plants, especially on islands. '''True rats''' are [[Omnivore|omnivorous]], capable of eating a wide range of plant and animal foods, and have a very high [[birth rate]]. When introduced to a new area, they quickly reproduce to take advantage of the new food supply. In particular, they prey on the eggs and young of forest birds, which on isolated islands often have no other predators and thus have [[Island tameness|no fear of predators]].<ref>{{cite web|url=http://www.issg.org/database/species/ecology.asp?si=19&fr=1&sts=&lang=EN|title=Rattus rattus (mammal)|publisher=Global Invasive Species Database|access-date=17 January 2015|url-status=dead|archive-url=https://web.archive.org/web/20151020062206/http://www.issg.org/database/species/ecology.asp?si=19&fr=1&sts=&lang=EN|archive-date=20 October 2015}}</ref> Some experts believe that rats are to blame for between forty percent and sixty percent of all seabird and reptile extinctions, with ninety percent of those occurring on islands. Thus man has indirectly caused the extinction of many species by accidentally introducing rats to new areas.<ref>{{cite web|url=http://scienceavenger.blogspot.ca/2007/12/humans-outdone-by-rats-for-causing.html|title=Humans outdone by Rats for causing Extinctions|publisher=Science Avenger|access-date=17 January 2015|url-status=live|archive-url=https://web.archive.org/web/20150119000642/http://scienceavenger.blogspot.ca/2007/12/humans-outdone-by-rats-for-causing.html|archive-date=19 January 2015|date=2007-12-05}}</ref>
==Rat-free areas==
[[File:Rat caged.webm|thumb|Rat trapped in a cage]]
Rats are found in nearly all areas of Earth which are inhabited by human beings. The only rat-free continent is [[Antarctica]], which is too cold for rat survival outdoors, and its lack of human habitation does not provide buildings to shelter them from the weather. However, rats have been introduced to many of the islands near Antarctica, and because of their destructive effect on native flora and fauna, efforts to eradicate them are ongoing. In particular, [[Bird Island, South Georgia|Bird Island]] (just off rat-infested [[South Georgia Island]]), where breeding seabirds could be badly affected if rats were introduced, is subject to special measures and regularly monitored for rat invasions.<ref>{{cite web |url=http://www.antarctica.ac.uk/about_antarctica/environment/wildlife/non_native_species.php |title=Preventing the introduction of non-native species to Antarctica |publisher=British Antarctic Survey |access-date=17 January 2015 |url-status=dead |archive-url=https://web.archive.org/web/20150108071223/http://www.antarctica.ac.uk//about_antarctica/environment/wildlife/non_native_species.php |archive-date=8 January 2015 }}</ref>
As part of [[island restoration]], some islands' rat populations have been eradicated to protect or restore the [[ecology]]. [[Hawadax Island, Alaska]] was declared rat free after 229 years<ref>{{Cite web |last=Rosen |first=Yereth |date=2009-06-13 |title=Hawadax Island Is Rat-Free |url=https://www.reuters.com/article/scienceNews/idUSTRE55B66920090612/ |access-date=2024-03-10 |website=Reuters}}</ref> and [[Campbell Island, New Zealand]] after almost 200 years.<ref>{{Cite web |last=Cooper |first=John |date=2022-12-13 |title=Pioneering rodent eradication in the sub-Antarctic: the Campbell Island Rat Eradication Project |url=https://mousefreemarion.org/pioneering-rodent-eradication-in-the-sub-antarctic-the-campbell-island-rat-eradication-project/ |access-date=2024-03-10 |website=Mouse-Free Marion |language=en-US}}</ref><ref>{{Cite web |title=Eradication—The Clearance of Campbell Island |url=https://www.nzgeo.com/stories/eradication-the-clearance-of-campbell-island/ |access-date=2024-03-10 |website=New Zealand Geographic |language=en-NZ}}</ref> [[Breaksea Island (Fiordland)|Breaksea Island]] in New Zealand was declared rat free in 1988 after an eradication campaign based on a successful trial on the smaller Hawea Island nearby.<ref>{{Cite journal |last1=Taylor |first1=R.H. |last2=Thomas |first2=B.W. |date=1989 |title=Eradication of Norway Rats (rattus Norvegicus) from Hawea Island, Fiordland, Using Brodifacoum |url=https://www.jstor.org/stable/24053177 |journal=New Zealand Journal of Ecology |volume=12 |pages=23–32 |jstor=24053177 |issn=0110-6465}}</ref><ref>{{Cite web |last=Guthrie |first=Kate |date=2020-03-22 |title=Rat eradication breakthrough — Breaksea Island 1988 |url=https://predatorfreenz.org/stories/breaksea-island-rat-eradication-breakthrough/ |access-date=2024-03-10 |website=Predator Free NZ Trust |language=en-US}}</ref>
In January 2015, an international "Rat Team" set sail from the [[Falkland Islands]] for the [[British Overseas Territory]] of [[South Georgia and the South Sandwich Islands]] on board a ship carrying three helicopters and 100 tons of rat poison with the objective of "reclaiming the island for its seabirds". Rats have wiped out more than 90% of the seabirds on South Georgia, and the sponsors hope that once the rats are gone, it will regain its former status as home to the greatest concentration of seabirds in the world. The South Georgia Heritage Trust, which organized the mission describes it as "five times larger than any other rodent eradication attempted worldwide".<ref>{{cite web |last= Gill, First= Victoria |title= South Georgia rat eradication mission sets sail |url= https://www.bbc.com/news/science-environment-30922255 |publisher= BBC |date= 23 January 2015 |access-date= 21 January 2015 |url-status= live |archive-url= https://web.archive.org/web/20150124123703/http://www.bbc.com/news/science-environment-30922255 |archive-date= 24 January 2015 }}</ref> That would be true if it were not for the rat control program in Alberta (see below).
The Canadian province of [[Alberta]] is notable for being the largest inhabited area on Earth which is free of true rats due to very aggressive government rat control policies. It has large numbers of native [[pack rat]]s, also called bushy-tailed wood rats, but they are forest-dwelling vegetarians which are much less destructive than true rats.<ref>{{cite web |url=http://pestcontrolcanada.com/wildlife-control/wood-rat-pack-rat/ |title=Bushy-Tailed Woodrat (Pack Rat) |publisher=Pest Control Canada |access-date=8 August 2017 |url-status=live |archive-url=https://web.archive.org/web/20170629085333/http://pestcontrolcanada.com/wildlife-control/wood-rat-pack-rat/ |archive-date=29 June 2017 }}</ref>
Alberta was settled by Europeans relatively late in North American history and only became a province in 1905. Black rats cannot survive in its climate at all, and brown rats must live near people and in their structures to survive the winters. There are numerous predators in Canada's vast natural areas which will eat non-native rats, so it took until 1950 for invading rats to make their way over land from Eastern Canada.<ref>{{cite web |url=http://www.issg.org/database/species/distribution_detail.asp?si=159&di=37410&sts=&lang=EN |title=Rattus norvegicus (mammal) – Details of this species in Alberta |publisher=Global Invasive Species Database |access-date=18 October 2014 |url-status=dead |archive-url=https://web.archive.org/web/20141026081724/http://www.issg.org/database/species/distribution_detail.asp?si=159&di=37410&sts=&lang=EN |archive-date=26 October 2014 }}</ref> Immediately upon their arrival at the eastern border with [[Saskatchewan]], the Alberta government implemented an extremely aggressive rat control program to stop them from advancing further. A systematic detection and eradication system was used throughout a control zone about {{convert|600|km|sigfig=1}} long and {{convert|30|km|sigfig=1}} wide along the eastern border to eliminate rat infestations before the rats could spread further into the province. Shotguns, bulldozers, high explosives, poison gas, and incendiaries were used to destroy rats. Numerous farm buildings were destroyed in the process. Initially, tons of [[arsenic trioxide]] were spread around thousands of farm yards to poison rats, but soon after the program commenced the [[rodenticide]] and medical drug [[warfarin]] was introduced, which is much safer for people and more effective at killing rats than arsenic.<ref>{{cite web |url=http://www1.agric.gov.ab.ca/$department/deptdocs.nsf/all/agdex3441 |title=The History of Rat Control In Alberta |publisher=Alberta Department of Agriculture and Rural Development |access-date=18 October 2014 |url-status=dead |archive-url=https://web.archive.org/web/20140925063521/http://www1.agric.gov.ab.ca/$department/deptdocs.nsf/all/agdex3441 |archive-date=25 September 2014 }}</ref>
Forceful government control measures, strong public support and enthusiastic citizen participation continue to keep rat infestations to a minimum.<ref>{{cite web |url=http://www1.agric.gov.ab.ca/$department/deptdocs.nsf/all/agdex816 |title=Rat Control in Alberta |publisher=Alberta Department of Agriculture and Rural Development |access-date=18 October 2014 |url-status=dead |archive-url=https://web.archive.org/web/20140926013539/http://www1.agric.gov.ab.ca/$department/deptdocs.nsf/all/agdex816 |archive-date=26 September 2014 }}</ref> The effectiveness has been aided by a similar but newer program in Saskatchewan which prevents rats from even reaching the Alberta border. Alberta still employs an armed rat patrol to control rats along Alberta's borders. About ten single rats are found and killed per year, and occasionally a large localized infestation has to be dug out with heavy machinery, but the number of permanent rat infestations is zero.<ref>{{cite news |url= https://www.theglobeandmail.com/news/national/on-the-frontlines-of-albertas-war-against-rats/article27504057/ |last= Giovannetti |first= Justin |title= On the frontlines of Alberta's war against rats |date= 26 November 2015 |publisher= Toronto Globe and Mail |access-date= 8 August 2017 |url-status= live |archive-url= https://web.archive.org/web/20170122205721/http://www.theglobeandmail.com/news/national/on-the-frontlines-of-albertas-war-against-rats/article27504057/ |archive-date= 22 January 2017 }}</ref>
==In culture==
{{Anchor|Culture}}
[[Ancient Romans]] did not generally differentiate between rats and mice, instead referring to the former as ''mus maximus'' (big mouse) and the latter as ''mus minimus'' (little mouse).<ref>{{Cite web|url=https://www.wigantoday.net/news/opinion/nature-notes-mus-maximus-1-173573|title=NATURE NOTES: Mus Maximus|website=www.wigantoday.net|language=en|access-date=2019-02-01|archive-url=https://web.archive.org/web/20190202042429/https://www.wigantoday.net/news/opinion/nature-notes-mus-maximus-1-173573|archive-date=2019-02-02|url-status=dead}}</ref>
On the [[Isle of Man]], there is a [[taboo]] against the word "[[Longtail (rat)|rat]]".<ref>Eyers, Jonathan (2011). ''Don't Shoot the Albatross!: Nautical Myths and Superstitions''. A&C Black, London, UK. {{ISBN|978-1-4081-3131-2}}.</ref>
===Asian cultures===
{{main|Rat (zodiac)}}
[[File:5 Rat and bat pendant TT-26.jpg|thumb|Chinese zodiac pendant with 5 rats climbing [[Ruyi (scepter)|ruyi]], bat at top of pendant]]
[[File:Two mice, Viet - Vietnam Museum of Ethnology - Hanoi, Vietnam - DSC02599.JPG|thumb|Two mice, Vietnam Museum of Ethnology - Hanoi]]
[[File:Chuột rước đèn.JPG|thumb|''Chuột rước đèn'' (The mouse carries the lamp), Vietnamese [[Đông Hồ painting]]]]
The rat (sometimes referred to as a mouse) is the first of the twelve animals of the [[Chinese zodiac]]. People born in this year are expected to possess qualities associated with rats, including creativity, intelligence, honesty, generosity, ambition, a quick temper and wastefulness. People born in a year of the rat are said to get along well with "monkeys" and "dragons", and to get along poorly with "horses".
[[File:Rat temple.jpg|thumb|right|Indigenous rats are allowed to run freely throughout the [[Karni Mata Temple]].]]
In Indian tradition, rats are seen as the vehicle of [[Ganesha]], and a rat's statue is always found in a temple of Ganesh. In the northwestern Indian city of [[Deshnoke]], the rats at the [[Karni Mata Temple]] are held to be destined for [[reincarnation]] as [[Sadhu]]s ([[Hindu]] holy men). The attending priests feed milk and grain to the rats, of which the pilgrims also partake.
===European cultures===
European associations with the rat are generally negative. For instance, "Rats!" is used as a substitute for various vulgar [[interjection]]s in the English language. These associations do not draw, ''per se'', from any biological or behavioral trait of the rat, but possibly from the association of rats (and [[fleas]]) with the 14th-century medieval plague called the [[Black Death]]. Rats are seen as vicious, unclean, parasitic animals that steal food and spread disease. In 1522, the rats in [[Autun]], [[France]] were charged and put on [[Animal trial|trial]] for destroying crops.<ref>{{cite web |url=https://hakaimagazine.com/features/in-defense-of-the-rat/ |title=In Defense of the Rat |last=MacKinnon |first=J. B. |date=September 26, 2023 |website=hakaimagazine.com |publisher=Hakai Magazine |access-date=October 8, 2023 |archive-url=https://web.archive.org/web/20231003061426/https://hakaimagazine.com/features/in-defense-of-the-rat/
|archive-date=October 3, 2023}}</ref> However, some people in European cultures keep [[Fancy rat|rats as pets]] and conversely find them to be tame, clean, intelligent, and playful.
Rats are often used in scientific [[experiment]]s; [[animal rights]] activists allege the treatment of rats in this context is cruel. The term "lab rat" is used, typically in a self-effacing manner, to describe a person whose job function requires them to spend a majority of their work time engaged in bench-level research (such as [[postgraduate education|postgraduate students]] in the sciences).
====Terminology====
Rats are frequently blamed for damaging food supplies and other goods, or spreading disease. Their reputation has carried into common parlance: in the [[English language]], "rat" is often an insult or is generally used to signify an unscrupulous character; it is also used, as a synonym for the term ''[[wikt:nark|nark]]'', to mean an individual who works as a police [[informant]] or who has turned [[state's evidence]]. Writer/director [[Preston Sturges]] created the humorous alias "Ratskywatsky" for a soldier who seduced, impregnated, and abandoned the heroine of his 1944 film, ''[[The Miracle of Morgan's Creek]]''. It is a term ([[noun]] and [[verb]]) in criminal slang for an [[informant]] – "to rat on someone" is to betray them by informing the authorities of a [[crime]] or misdeed they committed. Describing a person as "rat-like" usually implies he or she is unattractive and suspicious.
Among [[trade union]]s, the word "rat" is also a term for nonunion employers or breakers of union contracts, and this is why unions use [[inflatable rat]]s.<ref>{{cite web |url=http://nj.npri.org/nj98/07/power&privilege.htm |title=Nevada Journal: Louts and the Rat World |publisher=Nj.npri.org |access-date=2012-09-24 |url-status=dead |archive-url=https://web.archive.org/web/20130520200437/http://nj.npri.org/nj98/07/power%26privilege.htm |archive-date=2013-05-20 }}</ref>
===Fiction===
{{See also|Fancy rat#Fiction}}
[[File:Alaska Death Trap.jpg|upright|thumb|[[Imperial Japan]] depicted as a rat in a [[World War II]] United States Navy propaganda poster.]]
Depictions of rats in fiction are historically inaccurate and negative. The most common falsehood is the squeaking almost always heard in otherwise realistic portrayals (i.e. non[[anthropomorphic]]). While the recordings may be of actual squeaking rats, the noise is uncommon – they may do so only if distressed, hurt, or annoyed. Normal vocalizations are very high-pitched, well outside the range of human hearing. Rats are also often cast in vicious and aggressive roles when in fact, their shyness helps keep them undiscovered for so long in an infested home.
The actual portrayals of rats vary from negative to positive with a majority in the negative and ambiguous.<ref name="clute">{{cite book|last=Clute|first=John|author2=John Grant |title=The Encyclopedia of Fantasy|publisher=St. Martin's Griffin|date=March 15, 1999|page=642|isbn=978-0-312-19869-5 }}</ref> The rat plays a villain in several mouse societies; from Brian Jacques's ''[[Redwall]]'' and Robin Jarvis's ''[[The Deptford Mice]]'', to the roles of Disney's [[The Great Mouse Detective#Voice cast|Professor Ratigan]] and Kate DiCamillo's [[The Tale of Despereaux|Roscuro]] and [[The Tale of Despereaux (film)|Botticelli]]. They have often been used as a mechanism in horror; being the titular evil in stories like ''[[The Rats (novel)|The Rats]]'' or H.P. Lovecraft's ''[[The Rats in the Walls]]''<ref name="clute"/> and in films like ''[[Willard (1971 film)|Willard]]'' and ''[[Ben (film)|Ben]]''. Another terrifying use of rats is as a method of [[rat torture|torture]], for instance in [[Room 101]] in George Orwell's ''[[Nineteen Eighty-Four]]'' or ''[[The Pit and the Pendulum]]'' by [[Edgar Allan Poe]].
Selfish helpfulness —those willing to help for a price— has also been attributed to fictional rats.<ref name="clute"/> Templeton, from E. B. White's ''[[Charlotte's Web]]'', repeatedly reminds the other characters that he is only involved because it means more food for him, and the cellar-rat of John Masefield's ''[[The Midnight Folk]]'' requires bribery to be of any assistance.
By contrast, the rats appearing in the [[Doctor Dolittle]] books tend to be highly positive and likeable characters, many of whom tell their remarkable life stories in the Mouse and Rat Club established by the animal-loving doctor.
Some fictional works use rats as the main characters. Notable examples include the society created by O'Brien's ''[[Mrs. Frisby and the Rats of NIMH]]'', and others include ''[[Doctor Rat]]'', and [[Rizzo the Rat]] from [[The Muppets]]. [[Pixar]]'s 2007 animated film ''[[Ratatouille (film)|Ratatouille]]'' is about a rat described by [[Roger Ebert]] as "earnest... lovable, determined, [and] gifted" who lives with a Parisian garbage-boy-turned-chef.<ref name="ebert">{{cite book |last=Ebert |first=Roger |title=Roger Ebert's Four-Star Reviews 1967–2007 |publisher=Andrews McMeel Publishing |year=2008 |page=637 |isbn=978-0-7407-7179-8 |quote=Remy, the earnest little rat who is its hero, is such a lovable, determined, gifted rodent that I want to know what happens to him next, now that he has conquered the summit of French cuisine. |url=https://books.google.com/books?id=v43dJNPMJIkC&pg=PA637}}</ref>
''[[Mon oncle d'Amérique]]'' ("''My American Uncle''"), a 1980 [[cinema of France|French film]], illustrates [[Henri Laborit]]'s theories on [[evolutionary psychology]] and [[human behavior]]s by using short sequences in the storyline showing lab rat experiments.
In [[Harry Turtledove]]'s science fiction novel ''[[Homeward Bound (Turtledove novel)|Homeward Bound]]'', humans unintentionally introduce rats to the ecology at the home world of an alien race which previously invaded Earth and introduced some of its own fauna into its environment. [[A. Bertram Chandler]] pitted the space-bound protagonist of a long series of novels, Commodore Grimes, against giant, intelligent rats who took over several stellar systems and enslaved their human inhabitants. "[[The Stainless Steel Rat]]" is nickname of the (human) protagonist of a series of humorous [[science fiction]] [[novels]] written by [[Harry Harrison (writer)|Harry Harrison]].
Wererats, [[therianthropic]] creatures able to take the shape of a rat,<ref name="MC1">{{Cite book |author1=David "Zeb" Cook |author-link=David "Zeb" Cook |author2=Steve Winter |author2-link=Steve Winter |author3=Jon Pickens |author3-link=Jon Pickens |author4=Jay Battista |author4-link=Jay Battista |display-authors=3 | title = [[Monstrous Compendium|Monstrous Compendium Volume One]] | year = 1989 | publisher = [[TSR, Inc.]] | isbn = 0-8803-8738-6}}</ref> have appeared in the fantasy or horror genre since the 1970s. The term is a neologism coined in analogy to [[werewolf]].{{citation needed|date=May 2020}} The concept has since become common in [[role playing game]]s like ''[[Dungeons & Dragons]]''<ref name="MC1"/><ref>[[Gary Gygax|Gygax, Gary]] and Robert Kuntz. ''[[Greyhawk (supplement)|Supplement I: Greyhawk]]'' (TSR, 1975).<br>[[Gary Gygax|Gygax, Gary]]. ''[[Monster Manual]]'' (TSR, 1977).<br>[[Aaron Allston|Allston, Aaron]], [[Steven Schend|Steven E. Schend]], [[Jon Pickens]], and Dori Watry. ''[[Dungeons & Dragons Rules Cyclopedia]]'' (TSR, 1991).<br>[[Ann Dupuis|Dupuis, Ann]]. ''[[Night Howlers]]'' ([[TSR, Inc.|TSR]], 1992).<br>{{cite journal| last = Swan| first = Rick| author-link = Rick Swan| title = Role-playing Reviews| journal = [[Dragon (magazine)|Dragon]]| issue = #192| page = 86| publisher = [[TSR, Inc.|TSR]]| location = [[Lake Geneva, Wisconsin]]|date=April 1993}}<br>[[Doug Stewart (game designer)|Stewart, Doug]], ed. ''[[Monstrous Manual]]'' (TSR, 1993).<br>{{cite journal| journal=[[Dragon (magazine)|Dragon]]| issue=251| title=Ecology of the Wererat|date=September 1998| last=Johnson| first= Kristin| publisher=TSR}}<br>[[Skip Williams|Williams, Skip]], [[Jonathan Tweet]], and [[Monte Cook]]. ''[[Monster Manual]]''. [[Wizards of the Coast]], 2000.<br>Poisso, Dean. "Animal Ancestry." ''[[Dragon (magazine)|Dragon]]'' #313 ([[Paizo Publishing]], 2003).</ref><ref>{{Cite book |author1=Bryan Armor |author2=Christine Gregory |author3=Ellen Kiley |author4=Steve Long |author5=Malcolm Sheppard |display-authors=3 | title =Dragons of the East | year =2000 | publisher =[[White Wolf Publishing, Inc.]] | isbn =1-56504-428-2 |page=92}}</ref> and fantasy fiction like the ''[[Anita Blake: Vampire Hunter|Anita Blake]]'' series.<ref>{{cite thesis |type=Tesis doctoral |last=Fusco |first=Virginia |date=2015 |title=Monstrous Figurations: Notes for a Feminist Reading |publisher=Universidad Carlos III de Madrid |pages=4, 122}}</ref>
====The Pied Piper====
{{main|Pied Piper of Hamelin}}
One of the oldest and most historic stories about rats is "[[The Pied Piper of Hamelin]]", in which a [[rat-catcher]] leads away an infestation with enchanted music.<ref>{{Cite web |title=The grim truth behind the Pied Piper |last=Kadushin |first=Raphael |website=BBC Travel |date=3 September 2020 |url= https://www.bbc.com/travel/article/20200902-the-grim-truth-behind-the-pied-piper}}</ref> The piper is later refused payment, so he in turn leads away the town's children. This tale, traced to [[Germany]] around the late 13th century, has inspired adaptations in film, theatre, literature, and even opera. The subject of much research, some theories have intertwined the tale with events related to the [[Black Plague]], in which [[black rat]]s played an important role. Fictional works based on the tale that focus heavily on the rat aspect include Pratchett's ''[[The Amazing Maurice and his Educated Rodents]]'', and Belgian graphic novel ''{{ill|Le Bal du Rat Mort|fr}}'' (''The Ball of the Dead Rat''). Furthermore, a linguistic phenomenon when a wh-expression drags with it an entire encompassing phrase to the front of the clause has been named [[pied-piping]] after "Pied Piper of Hamlin" (see also [[pied-piping with inversion]]).
==See also==
* [[Chicago rat hole]]
* [[List of fictional rodents]]
* [[Rat-baiting]]
* [[Rat king]]
* [[Rodentology]]
* [[Rat Guard]]
==References==
{{Reflist}}
==Further reading==
* [[List of books and articles about rats]], is a [[non-fiction]] list.
* Smith, Robert (Rat-catcher) (1786) ''[https://www.gutenberg.org/ebooks/74196 The universal directory for taking alive and destroying rats]
==External links==
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{{wikt}}
{{Wikiquote|Rats}}
{{Commons category|Rats}}
* [https://web.archive.org/web/20160303202127/http://brainmaps.org/index.php?p=speciesdata&species=rattus-norvegicus High-Resolution Images of the Rat Brain] (archived 3 March 2016)
* [https://web.archive.org/web/20050429174806/http://www.anim.med.kyoto-u.ac.jp/NBR/home.htm National Bio Resource Project for the Rat in Japan] (archived 29 April 2005)
* [http://www.ratbehavior.org/rats.html Rat Behaviour and Biology]
* [http://rgd.mcw.edu/ Rat Genome Database]
* {{Wikisource-inline|list=
** {{Cite NIE|wstitle=Rat|year=1905|short=x |noicon=x}}
** {{Cite EB1911|wstitle=Rat|short=x |noicon=x}}
** {{Cite Americana|short=1|wstitle=Rat|year=1920|noicon=x}}
}}
{{Murinae (Rattus)}}
{{Taxonbar|from=Q36396}}
{{Authority control}}
[[Category:Rats| ]]
[[Category:Mammal common names]]
[[Category:Rodents]]
[[Category:Scavengers]]
[[Category:Extant Pleistocene first appearances]]
[[Category:Storage pests]]
[[Category:Paraphyletic groups]]
[[Category:Articles containing video clips]]