Brown Rat

Distribution: Cosmopolitan

Size: 16‒24 cm

Weight: 150‒250 g

Life Span: 1 Year

Diet: Omnivorous

Social life: Gregarious

IUCN red list status: Least Concern



The Brown Rat is found on all continents of the earth. It has been introduced through human travel overseas to all continents. Rats are various medium-sized, long-tailed rodents.

They are considered as opportunistic survivors and often live with and near humans. It is an agile climber and good swimmer but in comparison with the Black Rat they usually don't run in heights over roof constructions and beams. They are very alert and can be aggressive when attacked. They usually build nest on the ground or in the underground, often they burrow under floors.

Social groups of rats are often formed of multiple males and multiple females. Male rats are called bucks, unmated females are called does, pregnant or parent females are called dams, and infants are called kittens or pups. A single female can produce a huge number of offspring, on average 4-7 young. Rats generally feed on fruit, grain, cereals, and other vegetation, but will feed on insects or other invertebrates if necessary. In most of the world they are considered as a pest, because of their high reproductive rates and the carriers of many diseases.