rat

A rodent of the genus Rattus (family Muridae), involved in the spread of some diseases, including bubonic plague.

- albino rats rats with white fur and pink eyes; used extensively in laboratory experiments.

- Wistar rats an inbred strain of rats, homozygous at most loci, produced by strict brother-sister inbreeding over many generations to develop animals for research with the same general genetic composition. [Wistar Institute]

* * *

repeat action tablet; rheumatoid arthritis test; right anterior trigone

* * *

rat 'rat n any of the numerous rodents (family Muridae) of Rattus and related genera that differ from the murid mice by their usu. considerably larger size and by features of the teeth and other structures and that include forms (as the brown rat, the black rat, and the roof rat) which live in and about human habitations and in ships, have become naturalized by commerce in most parts of the world, and are destructive pests consuming or destroying vast quantities of food and other goods and acting as vectors of various diseases (as bubonic plague)

* * *

(rat) any of numerous small rodents of the genus Rattus and related genera of the family Muridae; many are aggressive and omnivorous pests found around human dwellings. Rats not only cause great economic loss but also are vectors of disease; they harbor at least eleven species of intestinal parasites that are transmissible to humans, such as tapeworms, roundworms, and trichinae; and they are reservoirs for the infective agents of plague, typhus, Weil disease, and rat-bite fever. Albino mutants of some species are used as laboratory animals.