Description: The introduced black rat can be distinguished from other members of its family by: 1) dark reddish-brown upperparts with a darker mid-dorsal line, 2) white underparts tinged with pale yellow, 3) long bicolored tail (at least as long as the head and body) slender, scaly, and hairless, and 4) relatively large, broad and nearly hairless ears. The sexes are alike.
Size: The single known specimen from Kansas measures: total length 381 mm; tail 230 mm; hind foot 38 mm; ear 24 mm; weight 155 grams.
Range and Habitat: The only known locality of the black rat in Kansas is Wichita, but it is believed to have been more common before being replaced by the Norway rat. It may still exist in some Kansas towns and cities, and more information on the status of this alien rodent in the state is badly needed.
Reproduction: The black rat is a prolific breeder, reproducing throughout the year. It has five or six litters per year of as many as eleven young (average seven) per litter. The gestation period is 21 days. When born the young are hairless and helpless, with their eyes closed. In three weeks they are weaned, and in three months are capable of reproducing. The female has ten nipples.
Habits: The black rat is extremely adaptable and lives in close association with humans, inhabiting the upper stories and attics of buildings. Being excellent climbers, these introduced rodents maintain regular trails along and across supporting structures of buildings.
Food: The black rat is omnivorous, eating almost nay kind of available food. Considerable damage is done to foods stored by humans and to their property.
Remarks: Snakes and owls frequently search for these rats in barns. The greatest competitor for the black rat is its more aggressive near relative, the introduced Norway rat.