Norway Rat
Rattus norvegicus
NuisanceWhat it is
A large, heavy-bodied rat that commonly burrows at ground level and lives around sewers, dumpsters, foundations, crawlspaces, and food facilities. It is an excellent swimmer and usually travels along established runways.
How to recognize it
- Heavy-bodied, about 7 to 9 inches long, with a thick tail shorter than its body
- Blunt nose and small ears
- Brown or gray fur, with a lighter belly
- Droppings are capsule-shaped, about 3/4 inch long, with blunt ends
- Burrow holes about 2 to 3 inches wide beside foundations, under sheds, and under debris
- Greasy rub marks along walls and gnaw marks on wood, plastic, and pipes
Where you will find it
Burrows beside foundations, under sheds and slabs, near garbage and bird feeders, and in basements and crawl spaces. They are good swimmers and sometimes travel through sewers.
Found in every state.
Why it matters
They contaminate food, gnaw materials and wiring, and spread disease. They are strong swimmers and travel along set runways.
Look-alikes
- Roof rat: Slimmer, with a pointed nose, large ears, and a tail longer than its body. Climbs and nests in attics.
- House mouse: Much smaller, with droppings about 1/4 inch long.
- Muskrat: Larger, with a flattened tail, and lives near water.
What to do
- Remove food sources: use sealed trash bins, keep pet food indoors, and clean up beneath bird feeders.
- Keep vegetation, wood piles, and clutter away from the foundation.
- Don't try to trap or poison rats yourself. Poison is a hazard to children, pets, and wildlife.
- Clean up safely with gloves, a mask, and disinfectant, never sweeping dry droppings.
When to call a professional
- You see burrows around your foundation.
- You find signs inside the home.
- You see rats in daylight, or you've heard them in walls or under floors.
Questions
Are Norway rats dangerous?
They can spread germs through droppings and urine, contaminate food, and gnaw wiring and pipes. A cornered rat may bite.
Why am I seeing rats in daylight?
Daytime sightings can mean a large population or a disturbed nest, and are a good reason to call a professional.
Will a cat keep rats away?
Not reliably. Rats are large and wary, and most cats won't solve the problem.
Related reading
Related pests
Roof Rat
A slender, agile rat with a long tail that readily climbs and often nests above ground in attics, ceilings, trees, vines, and upper structural areas. It is especially common in warmer regions.
Read more →Rats
Large rodents that burrow around foundations or nest in attics, gnaw wiring and spread contamination. Sanitation and exclusion help, but rats usually call for a licensed professional.
Read more →Chipmunks
Small striped ground squirrels that burrow near foundations, landscaping, retaining walls, and gardens. They can disturb soil, raid birdseed, and occasionally enter garages or structures.
Read more →Deer Mice
Small mice with a brownish back, white underside, large eyes, and a distinctly bicolored tail. They are common in rural or wooded settings and may enter sheds, garages, attics, and homes.
Read more →This page is general information, not a diagnosis. Pests vary by region and situation, and an on-site inspection is the reliable way to know what you have.