Roof Rat in Coastal Alabama

Scientific name: Rattus rattus. Common name: roof rat, black rat, ship rat. Family: Muridae. Status in Mobile-Baldwin: dominant rat species in coastal Alabama, well established across both counties and especially common in waterfront and citrus-adjacent neighborhoods.

Identification

Adults are 13–17 inches total length, with the tail longer than the body. Body color ranges from dark brown to nearly black; underside varies. Ears are large, hairless, and pull-forward-to-cover-the-eye. Snout is pointed. Compare to Norway rat: larger body, shorter tail than body, smaller ears, blunter snout. Roof rats leave small dark droppings (12 mm) with pointed ends; Norway droppings are larger (18 mm) with blunt ends.

Biology and life cycle

Sexual maturity at 3–4 months. Females produce 3–6 litters per year of 5–8 young each, for an outdoor population doubling time as short as 2 months under good conditions. Lifespan in the wild is 12–18 months. Nocturnal, with a 6-PM-to-2-AM activity peak. Travel routes are remarkably consistent — same wires, same fence-tops, same eaves night after night.

Habitat and range in Mobile-Baldwin

Coastal and waterfront environments are the stronghold. Roof rats nest above ground in palm-frond skirts, attic spaces, garage rafters, dense ivy and bougainvillea, and old citrus trees. Gulf Shores, Orange Beach, Dauphin Island, Bayou La Batre, and the Mobile downtown waterfront see year-round populations. Inland Mobile and Baldwin neighborhoods see roof rats wherever mature trees touch structures.

Risk to homeowners

Disease vectors: leptospirosis, salmonellosis, hantavirus (regional rare), murine typhus (historical regional documentation). More commonly: contamination of stored food and pet food, structural damage from chewing through electrical wiring (significant fire risk), insulation damage in attics, and downstream secondary-pest pressure from rat carcasses inside walls.

Prevention

Trim tree limbs to 4 feet of clearance from any roof edge. Cap chimneys with rodent-rated screening. Replace torn soffit screens. Inspect garage door bottom seals annually. Cover attic gable vents with hardware cloth (1/4 inch). Eliminate fruit-tree windfall around the property — citrus and figs are roof-rat magnets in this region. Store pet food in metal containers, not plastic.

Treatment options

Exclusion first, then control. Closing entry points before baiting is essential — baiting alone produces dead rats inside walls. Snap traps with peanut-butter or hazelnut-spread bait placed perpendicular to travel paths are highly effective. Tracking patches and bait stations along established routes confirm activity reduction. Anticoagulant rodenticides require ADAI licensure and careful placement to avoid secondary pet/wildlife exposure.

When to call

Droppings in the attic, scratching sounds in walls at night, gnaw marks on roof eaves, or palm-frond rustling at dusk all warrant inspection. Call us: (251) 555-0100.

Related

See: Rodent Control Mobile · Local roof-rat coastal behavior · Compare to Norway rat