Norway Rat

Actual Size: 16″ (tail included)

Characteristics: The Norway rat is brown with a blunt nose and relatively small ears.

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 are known for their aggressive behavior and burrowing activity.
  • These rats are most active at night.
  • They gain access through quarter-sized holes, and beneath exterior doors.


Norway rats are known for being one of the more aggressive types of rodents. They are stocky, heavy-bodied rats and are larger than the roof rat. Found throughout the United States, Norway rats are commensal rodents, living near and dependent on the human habitat for survival. Norway rats will eat almost anything but prefer cereal grains, meats, fish, nuts, and some fruits. Like most rodents, Norway rats are most active an hour after sunset and just before dawn. The gnawing activity of Norway rats can cause considerable damage to homes, gardens, and structures. Norway rats are carriers of serious diseases, including jaundice, rat-bite fever, and salmonella.

Norway Rat Habitat

Norway rats are known to prefer burrows and tunnels in which to live. They usually dig their own, which are usually 2 to 3 inches wide and up to 6 and a half feet long. They also can inhabit burrows that were built by former animals or rodents. Norway rats are ground burrowing animals and construct burrows that are 2 to 3 inches in diameter and up to 6.5 feet in length. Burrows are constructed outdoors beside foundations and gardens. Norway rats are nocturnal and will enter homes at night in search of food, returning back to their burrow. If nests are found inside homes, they are typically in basements and crawl spaces. They also can be found in attics.

Norway Rat Behaviors and Threats

Due to their bigger size and aggressive behavior, Norway rats can be some of the most destructive pests. They can damage foundations, slabs, garden crops, and plants as they burrow and gnaw to find food and shelter. 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. Salmonella, leptospirosis, and rat-bite fever are among the dozens of diseases spread by these rats.

As soon as you notice Norway rats in your property, contact your local rodent control company for help.