Western Exterminators - Pest Control Services California, Arizona, Nevada

Rodents: Deer Mouse | House Mouse | Norway Rat (Brown Rat, House Rat, Wharf Rat, Sewer Rat) | Roof Rat (Black Rat, Ship Rat) | White-footed Mouse

	Common name:	Latin name:	Class:	Order:	Family:
	Norway Rat (Brown Rat, House Rat, Wharf Rat, Sewer Rat)	Rattus Norvegicus (Berkenhout)	Mammalia	Rodentia	Muridae

	Size:
	Average adult measures about 16 inches, but total head and body length is about 7-9 inches (18-25 cm); tail length is 6-8 inches (15-21 cm); weight is 7-18 ounces, up to 20.5 ounces.
	Characteristics:
	The Norway Rat did not originate in Norway; the name presumably is based on where this rat was classified. The body is heavy; 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 and body. Also called Brown Rat, Sewer Rat, Barn Rat, Water Rat, Grey Rat and Wharf Rat.
	Color:
	Brown with scattered black hairs, gray to yellow-white on underside.
	Droppings:
	Adult droppings are up to 3/4 inch (20mm) long, capsule shaped with blunt ends.
	Where Found:
	Central Asia, north of Caspian Sea, but now found around the world and throughout the U.S.
	Comparison:
	The Roof Rat is lighter in color than the Norway Rat and has a pointed muzzle, larger eyes, and larger ears; is uniformly colored, almost naked, and has a tail that is longer than the combined head and body length; droppings are spindle shaped and pointed at ends. Hispid Cotton Rat has a tail length of about half of its head and body, 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 and 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:
	Adapted to dry, treeless, grassy plains of its native area. Outdoors, burrows with hidden emergency exits are in soil along railroad embankments, river banks, rubbish piles, and under concrete.
	Food:
	Will eat various foods, but they prefer meat, fish, cereal, and dry dog food. They require a water source other than food. Norway Rats 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:
	Social. Many burrows may be in same area. Mature in 2-5 months, and live as adults for 6-12 months, longer in captivity. Pregnancy lasts 3 weeks. Newborns get hair after 1 week, open eyes in 2 weeks, and are weaned at 3-4 weeks. Females have 3-6 litters per year, 7-8 young per litter, with an average of 20 young weaned per year. Keen hearing, smell, taste, and touch with their long whiskers, but poor vision, and are also color blind. Can run, climb, jump, and swim. Nocturnal, and explore a lot, but cautious and shy away from newly introduced objects.
	Damage:
	They gnaw objects, eat stored food, and transmit disease by droppings, urine, bites, fleas and mites in their fur.
	Invasion:
	An opening larger than 1/2 inch (12mm) permits entry into structures.
	Control:
	Overall, the key to rodent control involves sanitation, harborage elimination and rodent-proofing the structure. When inspecting for Norway Rats, look for evidence of burrows outside the structure. Gnaw marks, droppings, footprints, ‘tail-drag’ marks, and dark greasy markings from rubbing against surfaces are signs of infestation. Eliminating clutter and excess storage will allow for the setting of control measures and the monitoring of the population decrease. Cleaning up of spillage will enhance the chances of rodents visiting control measures. Elimination of rodent evidence will allow monitoring population control. Exclusion is an important aspect of rodent control in structures. Most of the rodent problems are due to indigenous species finding their way into our homes or business for food or shelter. Rodents can fit through small openings due to their ability to ‘flatten’ their bodies. ½ inch can allow entry for rats. It is important that a thorough inspection be performed for the purpose of identifying entry points and repairing them. This is the only way to achieve long-term control in areas were this rodent is indigenous. Once entry points have been repaired, use of mechanical trapping devices is recommended inside. We do not recommend the use of rodenticides inside residential properties. Rodenticides can be used outside as long as they are kept away from children or pets. When using any rodenticide, read the entire label prior to use. Follow all label directions, restrictions, and precautions. When dealing with long-term problems, we recommended using a professional exterminator for best results.