Norway Rats vs. Roof Rats: Which One Is in Your House?
Most people never get a good look at the rat. They hear it, find droppings, or see a tail disappear under the deck. Knowing which rat it is still matters, because the two common rats in the U.S. live in different parts of a house.
In Louisville the answer is usually easy. The University of Kentucky's pesticide training material on rodents says roof rats are not common in Kentucky. The rat in your basement or your alley is almost always a Norway rat.
Norway rat
Big and heavy, brown to gray-brown, with a blunt nose, small ears and a tail shorter than its head and body together. Norway rats are burrowers. They dig under slabs, sheds, stoops and foundations, they swim, and they like the ground floor and below: basements, crawl spaces, garages and sewers. Their droppings are large, about three-quarters of an inch, with blunt ends.
Roof rat
Smaller and sleeker, usually darker, with a pointed nose, big ears and a tail longer than its body. Roof rats are climbers. They live in trees, attics and upper walls and travel along fences and utility lines. Their droppings are smaller and pointed at the ends. They're a big deal in the Deep South and on the coasts, but they're not a common Kentucky pest.
Mouse
Much smaller than either rat, with big ears and droppings about the size of a grain of rice. A young rat can look like a big mouse. A young rat has big feet and a thick head for its size, while a mouse looks delicate. If it's mice, see mouse control.
Why it changes the plan
Because Norway rats live low, the work in Louisville focuses low: foundations, basement windows, crawl space vents, burrows, garages and drains. A rodent in the attic here is more often mice or a Norway rat that climbed up inside an old wall than a roof rat. Either way, tell the tech what you've seen and where. Our crawl space and basement page and attic page cover the two ends of the house.
- Norway rat: big droppings with blunt ends, burrows, basements and alleys
- Roof rat: pointed droppings, attics and trees, not common in Kentucky
- Mouse: rice-sized droppings, kitchens and walls, mostly fall and winter
Common questions
Can a Norway rat get into the attic?
Yes. They can climb, especially inside old walls without fire blocking or up a vine or downspout. They'd just rather stay low.
What does a rat burrow look like?
A hole about two to four inches across, often under something solid, with smooth, packed dirt at the opening.