Norway Rat – Rattus norvegicus

Norway Rat  –  Rattus Norvegicus

Color: Usually grayish-brown, but color varies from a pure gray to a reddish brown; hard to identify by color alone
Weight:  10-16 ounces; larger than Roof Rat
Length:  7-10 inches
Tail Length:   6-8 inches; shorter than the body
Body:  Heavy & thick body, blunt nose
Ears: Relatively small; close to body
Eyes: Large & protruding black eyes
Lifespan: 5 to 12 months
Droppings:   ¾ inch long with blunt ends; dark color; found in groupings

Reproduction of the Norway Rat

Litter Size: 8-12 pups per litter
Number of Litters: 4-7 per year
Sexual Maturity:  2-3 months
Gestation Period:  22 days
Breeding Season:   Indoors: All year – Outdoors: Spring & Fall
 
Norway Rat Feeding Habits

Daily Amount:   0.5-1 ounce
Daily Water:  1-2 ounce
Daily Food:  Cereal grains, meats, seeds, cockroaches, fruits, shrimp

Norway Rat Nesting

Nest Location:   Burrows in soil, sewers, basements, lower portion of buildings
Home Range:  25-100 ft. from nest
Active Periods:  Nocturnal; most feeding occurs 30 minutes after sunset and before sunrise

Telling Norway rats and Roof rats apart

Roof rat (Rattus rattus), also called black rat, ship rat Norway rat (Rattus norvegicus), also called brown rat
Overall appearance Medium-sized, slender rodent with large ears and a long, thin scaly tail (generally longer than body). Medium-sized chunky rodent with a scaly tail that is shorter than the body.
Color Black, gray, or brown Brown or gray
Weight up to 200 g 400-500 g
Ears Large, creased, flimsy Small, sturdy
Tail Tail longer than body, uniform in width. Tail is slender and prehensile. Charcoal grey. Tail shorter than body, fatter at base. Tail is fat and not prehensile. Pink or tan.
Muzzle Narrow, sharp and long Blunt, broad, and short. Heavy cheeks.
Locomotion Agile climber, doesn’t like swimming. Not as good a climber as roof rat, but good swimmer.
Habitat World-wide in warm climates. Human buildings, generally high up: attics, rafters, crossbeams of buildings. Form runways along pipes and wires World-wide. Human buildings, generally low down: in basements, on the ground floor, in sewers and subways, in burrows under buildings.
May also live in a feral state where cover is available.

Rats_RoofNorwayComparison