Roof Rat

Profile

Scientific name

Rattus rattus

Identification

Dark brown to black with a lighter belly, pointed muzzle, large thin ears, and a uniformly dark tail longer than the body.

Typical size

Body about 6-8 inches with a longer tail.

Behavior

Excellent climber, nocturnal, and travels established aerial routes. Nests in attics, soffits, palms and dense vegetation.

Habitat

Attics, soffits, wall voids, palm crowns, dense ivy and attached garages.

Diet

Fruit, nuts, seeds, pet food and food waste.

Lifecycle

Rapid reproduction with several litters per year in favorable conditions.

Why it matters

Roof rats contaminate insulation and stored items, damage wiring and ductwork, and carry disease organisms. Follow CDC guidance when cleaning contaminated areas.

DIY considerations

Attic trapping without closing roof-line access leads to endless recurrence, and disturbed insulation hides new activity.

Professional considerations

Larger rodent jobs combine trapping with exclusion at the roof line, plus follow-up to confirm the structure is closed.

Signs of activity

• Running and gnawing sounds in ceilings and walls after dark
• Capsule-shaped droppings with pointed ends in attic insulation
• Gnawed soffit, fascia or vent screening
• Greasy rub marks along beams and roof framing
• Damaged wiring or ductwork in the attic

Prevention

• Trim tree limbs and palm fronds back from the roof
• Screen roof, gable and soffit vents with metal mesh
• Seal utility penetrations and roof-line gaps
• Remove fallen fruit and secure pet food and trash
• Cut back dense ground cover against the structure

Sources

• CDC — Rodent control and cleanup
• US EPA — Rodenticides and rodent control