Adult roof rats reach 12 inches in length from nose to tip of tail.
The roof rat can range in color from light brown to dark gray to black with a lighter grey belly. Its tail is noticeably longer than its body length. It has a pointed nose, large eyes, and large ears.
The roof rat is smaller and slimmer than the Norway rat, and cannot compete with the Norway when space is limited. Roof rats are nocturnal and secretive, staying out of view by hiding in the foliage from landscaped environments. A normal life expectancy for them is one year or less. Roof rat fleas can transmit disease such as the plague. Roof rats enter structures in search of food and are extremely destructive to stored food products, crops, pipes, and electrical wires. They are excellent climbers and often gain entry into homes through holes around cabling vents. Their climbing skills allow them to easily climb onto homes to wander from rooftop to rooftop.
Roof rats feed heavily on the fruits, nuts, vegetables, or garden snails found in suburban landscaped areas.
A female roof rat will have three to four litters in her year one year of life with an average of eight to nine pups per litter.
Roof rats are much more aerial than Norway rats in their habitat selection and often live in trees or on vine covered fences. Roof rats can enter through any opening wider than ½ inch, they are excellent swimmers, can climb any rough surface, and can jump vertically about three feet.