Roof Rat

Category Rodents

Health Risk Medium

Damage Risk Medium

Nuisance Medium

Actual Size: 13 to 15” long including the tail

Characteristics: Slender. Typically grayish to dark gray to black.

Habits: As their name suggests, these rats sneak into roofs by climbing trees or nearby vines.

Commonly referred to as the “black rat” or “ship rat.”
Their tail is longer than the combined length of their head and body.
Frequently nest above ground in attics, trees, and other elevated locations.

Roof Rats in Wisconsin

Within the United States, roof rats are considered a significant pest risk along the West Coast, throughout the Southeast, and in coastal regions of Washington, Oregon, and California. These rodents are closely associated with human development and depend on buildings for food, shelter, and protection. Once inside, they typically establish themselves in attics, roof voids, eaves, and other elevated areas. One of the easiest ways to distinguish a roof rat from other rat species is by its tail. Unlike other rats, the roof rat has a hairless tail that extends beyond the combined length of its head and body, instead of a typical short, hairy tail.

Roof Rat Habitat

Roof rats naturally seek out elevated nesting locations, including tree canopies, climbing vines, and dense shrubs. They have specialized pads on their feet that allow them to grip narrow branches, and their long tails provide balance as they climb. During the night, roof rats leave their nests to search for food, traveling along utility wires, tree limbs, fences, and rooftops to reach attics, garage storage areas, woodpiles, and other sheltered locations. Scratching or scampering sounds overhead are one of the earliest indications that roof rats have moved into a home.

Roof Rat Behaviors, Threats, or Dangers

Roof rats are capable of transmitting diseases, including salmonella, leptospirosis, and rat-bite fever. As they search for food, they contaminate food for people, pets, and livestock with their droppings and urine. Their diet includes both plants and animals, but they are particularly attracted to citrus fruits. They also feed on pet food, birdseed, grease, meat, and even pet waste, making storage sheds and outdoor grills attractive feeding sites.

In addition to contaminating food, roof rats cause costly structural damage. They love to nest inside attics and wall voids, where their constant gnawing strips insulation from electrical wiring. Damaged wires can create serious fire hazards if left unaddressed.

If you suspect roof rats have invaded your Wisconsin home or business, contact a licensed rodent control professional to inspect the property.