Norway rat, a large brown rat with a blunt nose and short tail
Norway Rat (Rattus norvegicus)

Norway Rat

Reviewed by TJ Jackson, Certified ACE  ·  Updated 2026-08-11

Rattus norvegicus  |  Category: Rodents  |  ✓ Covered: All Seasons Rodent Plan

Norway rats are the big, ground-dwelling rat behind most rat problems in the Pacific Northwest. Heavy-bodied and brown, with a blunt nose and a tail shorter than its body, it burrows along foundations, under slabs, and beside woodpiles, and it works its way into basements, crawlspaces, and lower floors. Where the roof rat climbs, the Norway rat digs.

SizeBody 7″ to 10″, tail 6″ to 8″; heavy, up to a pound or more
ColorCoarse brown to gray fur with a pale gray belly
Top ID MarkerBlunt nose, small ears, thick tail shorter than the body
Where You Find ThemBurrows by foundations and woodpiles; basements, crawlspaces, sewers, lower floors
Active SeasonYear-round; nocturnal; stays low and close to the ground
RoleGnaws & burrows: damages structures, wires, and pipes
Plan Coverage✓ Covered under All Seasons Rodent Plan

What You Need To Know About Norway Rats

Frequently Asked Questions

How do I know it’s a Norway rat and not a roof rat?

Size and shape tell them apart. Norway rats are larger and heavier with a blunt nose, small ears that do not reach the eyes, and a thick tail that is shorter than the head and body. Roof rats are sleeker with a pointed nose, large ears, and a tail longer than the body. Behavior helps too: Norway rats stay low and burrow, while roof rats climb and nest up high.

Are Norway rats dangerous?

Yes, in a few ways. They gnaw constantly and will chew through wiring, pipes, and building materials, which can cause fires and water damage. They contaminate food and surfaces with droppings and urine, and they can spread diseases such as leptospirosis and salmonella. Their burrowing can also undermine slabs and foundations.

Where do Norway rats nest?

They are ground rats. Outdoors they dig burrows along foundations, under decks and sheds, beside woodpiles, and around garbage. Indoors they favor the lowest levels: basements, crawlspaces, and the spaces under and behind appliances. They are strong swimmers and sometimes travel through sewer lines.

How do I get rid of Norway rats?

Control combines sealing entry points (rats can use gaps as small as a half inch), removing food and harborage like woodpiles and clutter, and trapping or baiting to reduce the population. Because they burrow and can reinvade, a consistent, whole-property approach works much better than spot treatment.

Does the All Seasons Rodent Plan cover Norway rats?

Yes. Norway rats are covered under the All Seasons Rodent Plan, which includes interior and exterior monitoring, scheduled service, and free re-service between visits. Sealing and exclusion work to close entry points is quoted separately based on your home.

Quick Answer: Norway rats (Rattus norvegicus) are large, heavy brown rats with a blunt nose, small ears, and a thick tail shorter than the body. They are ground-dwellers that burrow along foundations and woodpiles and move into basements, crawlspaces, and lower floors. They gnaw through wiring and pipes, contaminate food, and can spread disease, so signs like fresh burrows or large droppings call for prompt action.

Most important distinction: The Norway rat is the low, burrowing rat: blunt nose, small ears, tail shorter than the body. That is what separates it from the sleek, big-eared, long-tailed roof rat that climbs and nests up high.

Behavior & Biology

The Norway rat (Rattus norvegicus), also called the brown rat or sewer rat, is the larger and heavier of the two rats found in the Pacific Northwest. A big adult can weigh a pound or more, with a stocky body, coarse brown-gray fur, a blunt muzzle, small ears that do not reach the eyes, and a thick tail noticeably shorter than its head and body.

Norway rats are ground animals. Outdoors they excavate burrow systems along foundations, under sheds and decks, and near reliable food and water such as garbage areas and pet feeding stations. Indoors they occupy the lowest levels of a building, and they are capable swimmers that sometimes enter through sewer and drain lines. They travel along established runways and leave greasy rub marks where they brush against walls.

Like all rats, they gnaw continuously to keep their incisors in check, and that gnawing is where much of the damage comes from: chewed wiring that can start fires, damaged pipes, and compromised building materials. Combined with their contamination of food and their role in spreading disease, that makes an established Norway rat population a problem worth resolving quickly and thoroughly.

What To Do If You Have Norway Rats

Norway rats are persistent and can reinvade, so control works best as a whole-property effort: seal the ways in, remove what feeds and shelters them, and reduce the population with the right stations and traps.

Seal the low entry points

Rats can push through gaps around a half inch. Seal openings around foundations, utility lines, vents, and door sweeps with rodent-proof materials, focusing on ground level where Norway rats travel.

Remove harborage

Clear woodpiles, dense ground cover, and clutter away from the house, and keep the area around foundations open. Fewer places to burrow and hide means fewer rats.

Cut off food and water

Secure garbage, pick up fallen fruit and pet food, and fix leaks and standing water. Rats settle where food and water are reliable.

Call a pro for burrows

Active burrows and an established population are best handled by a technician who can place and monitor stations safely and target the nest sites.

Plans That Keep Rodents Out

All Seasons Rodent Plan

$39/month

Setup fee ~$280 for initial service

Ongoing monitoring and control that keeps mice and rats out of your home year-round, with interior and exterior stations serviced on a regular schedule.

  • Interior & exterior monitoring
  • Scheduled seasonal service
  • Free re-service between visits
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Most Popular

Pest & Rodent Bundle

$47/month

Setup fee ~$280 for initial service

The most complete protection for your home: full rodent coverage plus year-round control of the insects and spiders PNW homeowners deal with most. One plan, one team.

  • Everything in the Rodent plan
  • Full pest coverage too
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Sealing and exclusion work (closing the gaps rodents use to get in) is quoted separately based on your home, and is not included in the monthly plan price. Your technician will walk the home and give you a clear estimate.