Norway Rat (brown rat, house rat, wharf rat, sewer rat)
Rattus norvegicus (Berkenhout)
Class: Mammalia
Order: Rodentia
Family: Muridae
Size: Norway rat adult's head+body length is about 7-9 in (18-25 cm); tail length is 6-8 in (15-21 cm); weight is 7-18 ounces, up to 20.5 ounces.
Characteristics: Heavy body; coarse, shaggy fur; blunt muzzle, small eyes, small ears with dense short hairs; scaly, 2-colored tail, which is darker on top, and is shorter than the length of its head+body.
Color: Norway rats are brown with scattered black hairs, gray to yellow-white on underside.
Droppings: Adult droppings are up to 3/4 in (20mm) long, capsule shaped with blunt ends.
Geographic Range: The Norway rat, which is also known as the brown rat, house rat, wharf rat, or sewer rat, is probably from central Asia, but now found around the world, and throughout the U.S.
Comparison with other rodents: Roof rat is lighter in color than the Norway rat, and has a pointed muzzle, larger eyes, larger ears; is uniformly colored, almost naked, and has a tail that is longer than the combined head+body length; droppings are spindle shaped and pointed at ends. Hispid cotton rat has a tail length of about half of its head+body length, coarse fur that is grayish on top and mixed buff, whitish and black on underside. House mouse is small, short, with a tail about the same length as head+ body; small droppings that are 1/8-1/4 in (3-6 mm) long, and rod shaped with pointed ends. Most native rats and mice have hairy tails; if not hairy, they look like they are made of ring-like segments.
Habitat: Outdoors, burrows of Norway rats are in the soil along railroad embankments, river banks, rubbish piles, and under concrete. Burrows have hidden emergency exits.
Food: Norway rats eat anything, but they prefer meat, fish, cereal, and dry dog food. They require a water source other than their food. They eat a lot at one time, returning to the same place, but quickly become shy of undesirable food or bait. They will travel to find food or water, gnawing through almost anything, even plastic or lead pipes.
Biology: Norway rats are social. Many burrows may be in the same area. These rats mature in 2-5 months, and live as an adult for 6-12 months, longer in captivity. Pregnancy lasts 3 weeks. Newborns get hair after 1 week, open their eyes in 2 weeks, and are weaned at 3-4 weeks. A female has 3-6 litters per year, 7-8 young per litter, with an average of 20 young weaned per year. They have keen hearing, smell, taste, and touch, with their long whiskers, but poor vision, and are also color blind. They can run, climb, jump, and swim. They are nocturnal, and explore a lot, but they are cautious and shy away from newly introduced objects.
Invasion: An opening larger than 1/2 in (12mm) permits entry of Norway rats into structures.
Damage: Norway rats gnaw objects, eat stored food, and transmit disease by droppings and urine, bites, and the fleas and mites in their fur.
Detection:
- Gnaw marks.
- Droppings.
- 4-toed front footprint in front of longer 5-toed hindprint.
- Dark greasy markings from fur rubbing against surfaces.
- Shallow burrows under plants.
- Greasy runways along walls and bare soil runways outdoors.
- Nibbled food.
Environmental Policy
The employees of American Pest Management are committed to improving the quality of life for all of our customers by providing the safest and most effective treatment for the management of pests which pose a threat to their health, property, and food supply. History has shown that neglecting to control pests such as cockroaches, mosquitoes, rodents, and ticks, and the misapplication of pest control products are equally dangerous.
