Identifying Norway Rats
Norway rats are easily identifiable by their coarse brown fur and large size. Adults can weigh about 200 to 500 grams. From nose to tail, they measure over 40 cm. The brown fur of the Norway rat lightens toward the underside. Despite its large size, its eyes and ears are small. The tail and ears are not covered in fur but possess a scaly texture.
Norway rats may be difficult to observe within a home, as they are nocturnal in nature. However, their droppings are often visible in homes they inhabit. These droppings measure about 18 to 20 mm in length and are capsule-shaped, with blunt ends.
Nests are also present in or near infested homes. Norway rats tend to line their nests with shredded paper, cloth and other fibrous material. Outside burrows are comprised of complex, underground networks with multiple exit holes. This burrowing behavior allows Norway rats access to outside food sources such as garbage cans or bird feeders.
Gnaw marks or holes in sacks of pet food may indicate a Norway rat infestation. Gnaw marks on doors or wooden walls and other hard, indoor surfaces are also signs of these rodents. Norway rats may leave footprints in dust or greasy markings on floors and walls.