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 … See more

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, minor propriocept… See more

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 rats and giant pouched rats are also sometimes kept. Pet rats behave differently f… See more

In 1895, Clark University in Worcester, Massachusetts, established a population of domestic albino brown rats to study the effects of diet and for other physiological studies. Over the years, rats have been used in ma… See more