Physical Characteristics

The adult Norway rat, also known as the brown rat, sewer rat, Hanover rat and wharf rat, is about 16 inches long, with a combined head and body length of nine inches and tail length of seven inches. Its body is stocky and muscular, built for digging and burrowing. Its fur is coarse and shaggy, and its color is usually brown with scattered black hairs, with its underside gray to yellowish white. The Norway rat has small ears and eyes, and a blunted muzzle. 


Norway Rat


Norway rats are well known for damaging and destroying material by gnawing. This rat will eat and contaminate stored food. Its bite is also a risk to humans, as this rat is a vector or carrier of diseases: salmonellosis, leptospirosis (aka Weil’s disease), bubonic plague. cowpox virus and trichinosis (spread to pigs, which infect humans). The Norway rat is nocturnal and, unlike mice, it will avoid new objects introduced into its territory. The Norway rat prefers to nest in the lower parts of structures – in basements, in piles of debris and stored things or merchandise – but this rat has also been found outdoors on or around riverbanks, railroad embankments, piles of rubbish and under concrete slabs. This rat’s lifespan is around one year, and in that time females will have two to four litters with aight or nine pups per litter. The Norway rat will eat anything, although it prefers high-protein items like meat, fish and cereal grains.


Once you’ve identified the Norway rat as your pest, you’ll want to clean up any sources for its food and water, deprive it of harborage, and rat-proof your house; keep in mind that a 1/2 inch opening is enough wiggle room for a rat to enter. Rat droppings and rub marks along walls will indicate high-traffic areas. If you choose to use traps, place them along walls, and use high-protein baits – meat, fish, cereal, even scrambled eggs or mac ’n’ cheese. One problem with bait stations that deliver a rodenticide is that some rats that consume the poison may climb inside walls or inaccessible areas before they die, and will not only smell bad while decomposing, but their corpses create food and harborage for developing insect larvae. Call Clark Pest Control, and a technician will come to your home or place of business with the answer to your rat problem.

Latin name: Rattus norvegicus