Rat

Rats are various medium-sized, long-tailed rodents. Species of rats are found throughout the order Rodentia, with the genus Rattus containing the most familiar rats. Other rat genera include Neotoma (pack rats), Bandicota (bandicoot rats) and Dipodomys (kangaroo rats). Among the best-known rats are the black rat and brown rat, both of which are native to Asia. Rats belong to the same subfamily as mice and are often distinguished based on 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 taxonomically specific. Like mice, they are known to invade properties for food, water, warmth, and shelter. There are 56 known species of rats in the world. Rats are found in every region inhabited by humans, excluding Antarctica. The most common species live alongside humans, but many diverse rat species are unique to island locations and are threatened by habitat loss or competition with other rodent species.