Scientific Name - Rattus rattus

Weight : 500 gm

Length : 16" total (6-8" body plus 6-8" tail)

Colour : Brown with black intermixed; Gray, white or black underside

Digestive tract : Yes

What are Roof Rats?

The roof rat is the smaller of the two commensal rats, as the size of the Norway rat is greater. Roof rats are sometimes called black rats or rats on board ships. The roof rat gets its name from its propensity in the upper sections of the buildings to find shelter. When inside, roof rats not only destroy materials by nibbling through them but they also contaminate stored food and act as vectors for harmful diseases.


What Do Roof Rats Eat?

Roof rats are omnivorous and able to consume almost all that they can find. However, when in season, they tend to feed on seeds, nuts, fruits, and berries. They can also feed on slugs and snails which can become a major part of their diet. Insects like American and brown cockroaches also feed on roof rats. They can consume shrimp, shellfish, and other marine species if they live near bodies of water.

Usually, roof rats eat at dusk and again before dawn, although they will forage several times a night and throughout the day. Roof rats are food hoarders in particular, meaning they were known to store stocks of such items as nuts and seeds. They tend to be in a sheltered or concealed setting when feeding.


With the spread of the extremely deadly bubonic plague, roof rats won their place in history. While transmission today is rare, there are still a handful of cases every year in the US. Roof rats may also bear fleas and transmit diseases such as typhus through fleas, contagious jaundice through water or food urine, rat-bite fever through bites, trichinosis through undercooked pork and salmonellosis through droppings. However, these rodents can cause food poisoning by contaminating surfaces in food or food storage.

As with many other species of rodents, when threatened, roof rats can exhibit aggression. They could be bite or chase in self-defence. Diseases like rat-bite fever can be transmitted through a bite or scratch of the roof rat. Rat-bite signs include vomiting, headache, fever, muscle and joint pain.

How to Get Rid of Roof Rats

Seal any gaps or cracks larger than a quarter with silicone caulk to avoid a roof rat infestation, and make sure all windows and vents are screened. Keep trees and shrubs trimmed away from the house and cut down overhanging branches on the roof. Roof rats are attracted to any accessible source of food, so they clean fruit that can fall from trees in the yard and hold garbage in tightly covered receptacles. Assure the pet food and other dry food are also kept in sealed containers. Eliminate any outdoor water sources such as leaky sprinkler heads, pet water bowls, and bird baths, in addition.