Norway Rat 

Norway Rat

Other Names: Brown Rat, Gray Rat, Common Rat, House Rat, Wharf Rat, Water Rat, Barn Rat, Sewer Rat, Super Rat

These "super rats" can reach 16" in length. Each female rat can give birth to 20 pups in her lifetime. Some factors affecting rat populations in cities include continuously mild winters, weather-related disasters, and encroachment of their habitats by new urban development.


Description | Reproduction | Diet | Habitat

Description of the Norway Rat

Rattus Norvegicus

Usually grayish-brown, but color varies from a pure gray to a reddish brown; hard to identify by color alone

10-16 ounces; larger than Roof Rat

7-10 inches

6-8 inches; shorter than the body

Heavy & thick body, blunt nose

Relatively small; close to body

Large & protruding black eyes

5 to 12 months

¾ inch long with blunt ends; dark color; found in groupings

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Reproduction of the Norway Rat

8-12 pups per litter

4-7 per year

2-3 months

22 days

Indoors: All year; Outdoors: Spring & Fall

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Diet of the Norway Rat 

0.5-1 ounce

1-2 ounce

Cereal grains, meats, seeds, cockroaches, fruits, shrimp

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Habitat of the Norway Rat

Throughout the US and Canada

Burrows in soil, sewers, basements, lower portion of buildings

25-100 ft. from nest

Nocturnal; most feeding occurs 30 minutes after sunset and before sunrise

Rat Habitats

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