The Norway rat is also known as the brown rat, gray rat, common rat, house rat, wharf rat, sewer rat, barn rat, and water rat. Their body is heavy and thick and about 7 to 10 inches long with an average weight of 10 to 17 ounces. Their coloring is usually gray-brown but may vary from pure gray to blackish or reddish brown. Their underside is a gray to yellow-white. Norway rats are often completely black. Their tail is shorter than the head and body, at about 6 to 8.5 inches. The tail is dark on top with a lighter underside.
The Norway rat’s nose and muzzle is blunt and they have an acute sense of smell. Their eyes are small and they are color blind with poor eyesight. Norway rats have ears that are close to the body that do not cover the eyes if they are bent forward. Their teeth are capable of gnawing through weeds, lead, aluminum, copper, cinder blocks, and uncured concrete. Their gnaw pattern is one eight inch. Norway rats have whiskers on their face and guard hairs on their sides and black to help this animal with poor eyesight stay safety against walls, under objects, and in burrows. Whiskers are also used to detect motion and test surfaces before stepping on them.
Identifying Norway Rat Droppings
Norway rats average about 30 to 180 droppings per day. Their droppings are about 2cm or less in length. Fresh droppings are soft and dark in color. Norway rats are omnivores and prefer meats, fish, flour, cereal grains, fruits, and vegetables. They eat almost any human food. Rats visit fewer food sites than mice, but actually eat more at each site. They consume about 3/4 to 1lb of food each day.