Black Rat

Scientific Name
Rattus rattus
Also Known As
Roof Rat, House Rat, Ship Rat
All of Florida
Almost Anything
Life Expectancy
1 Year
The Black Rat
Rount-tailed muskrat conservation status - endangered

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Black Rats in Central Florida

The black rat (Rattus rattus) is an agile, arboreal rodent that can become established in and around homes and buildings in central Florida’s urban areas. Also known as the roof rat, black rats are adept climbers that nest above ground in trees, palm fronds, and attics.

This guide covers black rat identification, biology, behavior, health risks, and prevention and control methods for central Florida.

Appearance and Identification

Black rats have slender, lightweight builds with these key juvenile and adult features

Juvenile Black Rat

Adult Black Rat

  • Size: Adults can reach 16 inches (40 cm) long including the tail and weigh 4 to 10 ounces (113 to 283 grams). Their bodies alone grow 6 to 8 inches (15 to 20 cm) long.
  • Tail: The tail is longer than the body at 6 to 8.5 inches (15 to 22 cm) in adults. It is scaly with sparse hairs.
  • Fur: Adults are black to brownish-black on top and lighter grayish-white on the belly. The fur is moderately long and coarse.
  • Head: Pointed nose, large protruding eyes, and big ears compared to other rat species.
  • Feet: Long, slender toes adapted for clinging and climbing. Hind feet are narrower.
Adult Black Rat

Juvenile Black Rat

  • Size: Newborns are about 2 inches (5 cm) long and weigh around 1 ounce (28 grams). They reach 7-9 inches (18-23 cm) long including the tail by 5-6 weeks old.
  • Fur: Juvenile black rats have grayish fur that is short and soft as they grow.
  • Features: Large head, feet, ears, and rounded nose relative to their smaller juvenile body size.

Black rats are lankier than Norway rats with larger ears and tail. They’re incredibly agile climbers but poorer burrowers than Norway rats.

Maturation Rate

Young black rats grow rapidly, reaching independence within 1 month after birth. They achieve reproductive maturity around 3-4 months old. Adult size is attained by 3 months of age.

Habits and Behavior

Black rats are nocturnal and most active at dawn and dusk. They prefer elevated habitats like trees, utility poles, and upper levels of buildings. Black rats are adept climbers and travel along overhead utility lines, pipes, cables, and ropes. Inside structures they inhabit attics and walls, moving across ceilings and upper edges.

Outdoors black rats nest in palm fronds, dense ivy, and trees. They can access buildings through the tiniest openings with their nimble climbing and gnawing abilities. Black rats tend to be solitary compared to Norway rats.

Reproduction and Lifespan

Females begin breeding as early as 2-3 months old and can produce up to 6 litters per year. Typical litter size is 6 to 8 young and the gestation period lasts 21-23 days. Average lifespan in the wild is about 1 year but females may reach 18 months. Their high reproductive capacity allows quick population recovery after control efforts.