Norway Rat


Actual Size: 16” long including the tail

Characteristics: Robust bodies. Typically grayish-brown can be reddish-brown to blackish.

Habitat: Known to create 6.5 feet long burrows along property lines and gardens. Will nest in basements and crawl spaces of homes.


  • Norway rats can be seen at dusk and dawn, but rarely during the day.
  • They typically nest in burrows or pre-existing holes outdoors.
  • They gain access through quarter-sized holes, and beneath exterior doors.

Norway Rats in Knoxville TN

In Knoxville, Norway rats getting into buildings can become a huge problem in the winter. When the weather begins to drop, rodents may try to seek shelter inside your home.

These rats are nocturnal and can run, climb, jump, swim, and more. They will eat nearly any type of food, but if given a choice, they select fresh food over stale or contaminated foods. They prefer cereal grains, meats and fish, nuts, and fruit. Food items in household garbage offer a balanced diet and also satisfy their moisture needs. When food sources become scarce, Norway rats may resort to cannibalism and prey on younger, weaker rats. In general, the rodents are opportunistic and feed on anything discovered while foraging. They are also larger than other types of rodents and rats, which leads to them occasionally being more destructive.

Norway Rat Habitat

Norway rats prefer to live in underground tunnels or burrows. Inside, they are often found in crawl spaces, basements, attics, or ceiling areas. Burrows of new, establishing rat populations are between 12-20 inches long. As the population grows, the burrows are enlarged and connect with other burrows to form a network of underground tunnels. 

Ground burrows usually have one central opening used for an entrance or exit and a couple of holes used for escaping. As the rat population increases and if food or water sources are limited, fighting will begin to defend territories. Dominant rats feed at night and are mostly nocturnal. The rats lower in rank are forced to reside in a section of the burrow further from food or water sources. They will feed and be active when the dominant rats are not active. Seeing rats active during the daytime often indicates a large population.

Norway Rat Behaviors, Threats, or Dangers

Norway rats are among the most dangerous types of rats. They burrow and gnaw to find food and shelter and can damage foundations, slabs, garden crops, and plants. Inside homes, Norway rats may cause extensive damage when nesting in walls and attics. 

Accounts of rodents starting fires through the gnawing of electrical wires have been widely reported. Chewed, exposed wires inside walls can spark, causing interior walls to catch fire. 

When foraging for food, these rats consume and contaminate food meant for humans, pets, and livestock. Even if you don’t directly come in contact with a rat, you can become sick by touching rat-contaminated food and cooking surfaces. Salmonella, leptospirosis, and rat-bite fever are among the dozens of diseases spread by Norway rats.

If you are dealing with a Norway rat problem in your Knoxville area home, always contact a licensed rodent control company.