Roof rats are blackish or brownish medium-sized, slender rats. They have long, naked, scaly tails that are usually longer than the head and body combined.
Roof rats live closely with humans. Typically, they make their homes in attics, rafters, and crossbeams in buildings, running along pipes, beams or wires, up and down the studding, or along the horizontal ceiling joists. They often leave a dark-colored layer of grease and dirt to mark their travel ways. The roof rat is largely nocturnal; you will only see them in the daytime if populations are particularly high. . In the southern United States, however, the roof rat is more common than the Norway rat.
Roof rats eat a variety of food items, including grains, meats, and almost any item that has nutritious value. They breed throughout the year, with two peaks of production in February and March and again in May and June. The period of least activity is in July and August. The gestation period of the roof rat is approximately 21 days, and the number of young per litter averages around seven. The young rats at birth are naked, blind, and nearly helpless.
The roof rat is destructive to property and food items. It also easily transmits human diseases.