Norway Rats in NYC: Signs, Burrows and What Actually Works
The Norway rat is the rat you see on New York sidewalks. Knowing how it lives makes it much easier to keep it out of your building.
Identification
- Body about 7 to 10 inches, plus a tail about as long.
- Brown to gray fur, blunt nose and small ears.
- Capsule shaped droppings about three quarters of an inch long.
- Grease marks along baseboards, pipes and walls where bodies rub.
Where Norway rats live
They burrow in soil along foundations, under stoops and sidewalks, beside trash areas and in garden beds. Burrow openings are roughly two to four inches wide with smooth edges and no spider webs. They also use sewer lines and travel between blocks underground, then come up wherever food is easy to reach.
How they get inside
A Norway rat needs about a half inch gap. Common routes are foundation cracks, utility penetrations, gaps at cellar doors and broken or missing vent screens. Once inside, they use basements, crawl spaces and wall voids, and can reach upper floors along pipes.
When activity peaks
Activity rises in fall as temperatures drop and rats look for warm shelter. Good timing for proofing is late summer, before the move indoors. Construction and sewer work can also push colonies onto nearby properties.
What actually removes them
- Inspect the exterior and interior to map burrows, runways and openings.
- Treat active burrows and use tamper resistant stations and traps on the runways.
- Seal entry points with metal and cement based materials.
- Cut off food and water: lidded trash, no outdoor pet food, repaired leaks.
- Monitor until activity reads zero.
Our rat control service follows this order, and our brownstone guide covers the sealing details.
Frequently Asked Questions
How big is a Norway rat?
About 7 to 10 inches of body plus a tail of similar length, which is much larger than a mouse.
What do rat burrows look like?
Smooth edged holes about two to four inches wide in soil near foundations, stoops, fences and trash areas, often with worn paths leading to them.
Why do rats come back after treatment?
Because the structure was not sealed and food or shelter is still available. Treatment and exclusion have to work together.
Sources
Rules and numbers on this page come from these public sources. Check them for the latest wording, since agencies update their pages.
- NYC Health Department: What happens to your rat complaint (PDF)
- HPD: Integrated Pest Management guide (PDF)