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Rat(Redirected from Rats)
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50 species; see text The term rat is also used in the names of other small mammals which are not true rats. Examples include the wood or pack rat, a number of species loosely called kangaroo rats and the Bandicoot Rat , Bandicota bengalensis. In Western countries, many people keep domestic rats as pets. Descendants of Norwegian rats bred for research, these animals are often called "fancy rats", "coloured rats" or "colour rats." Domesticated rats tend to be both more docile than their wild ancestors and more disease prone, presumably due to inbreeding.
VarietiesThere are over 50 species of rats, the most well-known of which are the Brown Rat, Rattus norvegicus; the Black Rat, Rattus rattus; and the Polynesian Rat, Rattus exulans. These three common species often live with and near humans, share their food and spread disease. At least one of these three species occurs on over 80% of island groups around the world and they have caused about half of bird and reptile extinctions. The Black Plague is believed to have been spread by rat-borne parasites. Rats are also blamed for damaging food supplies and other goods. They have a very poor reputation; in the English language, "rat" is an insult and "to rat on someone" is to betray them by denouncing a crime or misdeed they committed to the authorities. Rats might eat each other in stressful environments or when the number of rats in a space is very high, but cannibalism to prevent diseases from spreading is normal, where dead rats are eaten before they start spreading diseases. Not all rats spread diseases. Some can make fine pets. Rats in the laboratoryLike mice, rats (especially albino Rattus norvegicus) are frequently subjects of medical, psychological and other biological experiments due to their rapid growth to sexual maturity and because rats are easily kept and bred in captivity. Scientists have bred many strains or "lines" of rats specifically for experimentation. However, these lines are generally not transgenic because the easy techniques of genetic transformation that work in mice do not work in rats. This has frustrated many investigators, who regard many aspects of behavior and physiology in rats as more relevant to humans and easier to observe than in mice, but who wish to trace their observations to underlying genes. As a result, many researchers have been forced to study questions in mice that might be better pursued in rats. In October 2003, however, researchers succeeded in cloning two laboratory rats by the problematic technique of nuclear transfer. This may lead to more rats being used as genetic research subjects. Rats in cultureIn imperial Chinese culture, the rat (sometimes referred to as a mouse) is the first of the twelve animals of the Chinese zodiac. Consequently every twelfth year is known as a "year of the rat" in the Chinese calendar. People born in such years are expected to possess qualities associated with rats. These include creativity, honesty, generosity, ambition, a quick temper and wastefulness. "Rats" (i.e. 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." The stereotypes associated with rats in Western civilization are less complimentary. Rats are seen as vicious, unclean, parasitic animals that steal food and spread disease. When anthropomorphized, rats are usually depicted as selfish, crude and untrustworthy, with the characters of The Secret of NIMH being the major exception. Describing a person as ratlike usually implies they are unattractive and suspicious. By contrast, mice are stereotyped as cute and bourgeois. See also
Taxonomy of RattusThe genus Rattus is a member of the giant subfamily Murinae. There are several other murine genera that are sometimes considered part of Rattus. These are: Lenothrix , Anonymomys , Sundamys , Kadarsanomys , Diplothrix , Margaretamys , Lenomys , Komodomys , Palawanomys , Bunomys , Nesoromys , Stenomys , Taeromys , Paruromys , Abditomys , Tryphomys , Limnomys , Tarsomys , Bullimus , Apomys , Millardia , Srilankamys , Niviventer , Maxomys , Leopoldamys , Berylmys , Mastomys , Myomys , Praomys , Hylomyscus , Heimyscus , Stochomys , Dephomys , and Aethomys . The genus Rattus proper contains 56 species. A subgeneric breakdown of the species has been proposed, but does not include all species. The five groups are:
The following list is alphabetical. Species of Rats
Further reading and references
External links
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