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 are known to be more aggressive than other rats.
  • They gain access through quarter-sized holes, and beneath exterior doors.
  • Once inside,t heir burrowing and gnawing can cause property damage.

Norway Rats in Southern California

Norway rats are extremely territorial and much larger than other rats. Their droppings are much larger, around 3/4″, and combined with shed hair and dander can be a significant source of indoor allergens. 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 burrow in the ground. They 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. On some occasions, they will also inhabit burrows leftover from previous rats or animals. 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 but also in upper levels of the property.

Norway Rat Behaviors & Threats

Norway rats can cause a significant amount of damage in a property. They 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 Norway rats.

If you have a Norway rat infestation in your Los Angeles Metro area property, always contact a licensed rodent control company.