Rattus norvegicus
ID
- Coarse fur
- Prominent, naked ears
- Nearly naked, scaly tail
- Brown upper parts with scattered black hairs
- Pale gray or grayish brown underparts
Distribution
Most of North America. Non-native.
Reproduction
- Can breed year-round if shelter and food are adequate
- Gestation lasts 21 to 23 days but may last longer if the female is still nursing a previous litter
- Highly variable litter numbers, but usually 6 to 8 young produced (Whitaker)
- Females can mate again within hours of giving birth (Audubon)
Behavior
- Largely nocturnal
- Very cautious, actual numbers usually unknown because of skill in hiding (Whitaker)
- Can climb, swim, and burrow
- Builds complex burrows underground with multiple tunnels, exits, and chambers (Audubon)
Food Habits
- Can eat up to a third of its body weight in a day
- Will eat almost anything, including soap, candy, milk, meat, eggs
Size/Life Cycle
- Average Measurements: 320-480 mm (total length), 300-540 g (total weight) (Whitaker)
Predators
- Cats, dogs, snakes, hawks, owls, weasels, humans (poison, traps) (Whitaker)
Habitat
- Wherever food and shelter is available. (Whitaker)