One of several species of small rodents of the genus Rattus (formerly included in Mus) and allied genera, of the family Muridae, distinguished from mice primarily by being larger. They infest houses, stores, and ships, especially the Norway rat, also called brown rat, (Rattus norvegicus formerly Mus decumanus), the black rat (Rattus rattus formerly Mus rattus), and the roof rat (formerly Mus Alexandrinus, now included in Rattus rattus). These were introduced into America from the Old World. The white rat used most commonly in laboratories is primarily a strain derived from Rattus rattus.

available as inbred, outbred and mutant strains. They have been generally beaten as a model by their mice brethren, as the molecular tools that became available (stem cells, knockout genes, etc). Rat embryos do have the advantage of being much larger than mouse embryos and easy to breed. Rat development is also generally 1 day behind from mouse. Worm

any of various long-tailed rodents similar to but larger than a mouse

kiore Rats are yet another animal that has been introduced into New Zealand by humans. There are three species of rats that have been brought to New Zealand: the Pacific rat or kiore, the ship rat and the Norway rat. Rats eat a wide variety of foods including invertebrates, plant seedlings and fruits, frogs, lizards, bats, small birds and bird eggs.

Rodent, generally a pest but also the miners best friend

Committee for a Standardized Karyotype of Rattus norvegicus. Standard karyotype of the Norway rat, Rattus norvegicus. Cytogenet Cell Genet. 1973;12(3):199-205. Levan G, Hedrich HJ, Remmers EF, Serikawa T, Yoshida MC. Standardized rat genetic nomenclature. Mamm Genome. 1995;6:447-448.