Roof Rats

The Roof Rat

Roof rat roof rats The Roof Rat (Rattus rattus Linnaeus) is smaller in size than the Norway Rat. Another difference is that the Roof rat is more slender with a longer tail than the Norway rat.

The Roof rat also called gray-bellied rat, white-bellied rat, Alexandrine rat, black rat and ship rat.

Its origins go to the tree forests of Southeast Asia and are adept for climbing vines, wires, and narrow ledges.

They are located in the coastal areas of the USA since they do not adapt well to cooler temperatures. It is a more skittish rat than the Norway rat, being sensitive to any new change in the environment.

They are common rodents in attics if found inside. Many times, you may hear them in the walls or attic area. When inspecting for roof rats, look for their droppings.


roof rats, norway rats, house mice Roof rats have pointed noses and large ears and are often mistaken for House Mice. 

The head and feet of adult house mice are proportionally smaller than their bodies, while young rats have larger heads and feet in comparison to their bodies.

Commensal Rodent Identification

roof rat

The fur of Roof rat is smooth, while the fur of the Norway rat is rough and shaggy.

The adult Roof rat is about 7-10 inches long and weighs about 5-9 ounces. The Roof Rat has a long tail which is longer than the combined length of the head and body. If you pull the tail back over the body, it will reach over its head.

Inspecting Roof Rat Infestation

rat droppings
  • The Roof Rat Feces (droppings ) are spindle shaped and reach about 1/2 inch in size.The Norway Rat's droppings have a capsule shape.

  • Roof rats will also make tunnels through insulation and will leave chew marks (wood, pipes).

  • The tail markings and hind feet markings of the Norway Rat and of the Roof Rat are hard to differentiate between each other.

  • Runways for Roof Rats may be difficult to determine; look for their feces.

  • Refer to the section on Rodent inspection.


Roof Rats Diet

Roof rats will eat meat and grain, but their preferences are fresh fruits, vegetables, seeds, and nuts. They will eat snails, slugs, and insects as well. Roof rats will eat smaller portions of food compared to Norway rats. Naturally, they will eat in several different places, which will be an important strategy when you bait and trap. It is more important to place more traps and bait placements in several locations. They prefer to feed under cover and seek shelter when feeding. Bait stations will provide a shelter that they prefer.

Roof Rats Habits and Biology

roof rat on beam
  • The Roof Rats become sexually mature in just a couple months. Females become sexually mature in 68-90 days with 5-8 pups per litter. They have 4-6 litters per year.
  • Because the Roof Rats climb well, common nesting sites are above the ground. They will nest in trees, attics, voids along the roof line, and in ceilings. Like squirrels, they enter homes and are found in attics. In the absence of Norway rats or if their population grows, they can be found in burrows or piles of rocks.
  • Dense vegetation, lush landscapes, fruit trees, dog areas will attract Roof rats. They seek cover. They will also construct globular leafy nests in trees and enter buildings by tree branches, utility lines.
  • Roof Rats are suspicious like Norway Rats. Be patient in trapping and baiting. It may take a few days for them to adjust to a new change in the environment and take the bait or get trapped.
  • Peak times for Roof Rat activity is at dawn or dusk; they are nocturnal. If they are heard during the day, the population is large.

* By Kilessan (Own work) [CC BY-SA 3.0 (], via Wikimedia Commons