Roof rats are notorious for spreading disease – historically the highly dangerous bubonic plague. They support many ectoparasites and urinate on and contaminate food. They are also a dangerous pest since they will chew on wires and start electrical fires.

• Roof rats are largely commensals and live in close association with people. They travel along pipes, beams or wires, around the studding, or along the horizontal ceiling joists, often leaving a dark-colored layer of grease called “rub marks”.
• They breed throughout the year, with two peaks of production in February & March and in May & June. The gestation period is approximately 21 days, and the number of young per litter averages about 7.
• In residences where rats may be living in the attic and feeding outdoors, the damage may result in tearing up insulation for nesting or gnawing electrical wiring. Roof rats are not exclusive to the roof and attics; they may also get into the kitchen or any other area with stored food products.
• Ranging in size from 6 to 8 inches in length, not including their tails, they have very poor vision and are color blind. However, their other senses (hearing, smell, touch and taste) are extremely refined.
• Scientific name “Rattus rattus,” they are sometimes referred to as “black rat” since their coloration can be a lot darker than other rats or mice.