Roof rats are small rats and may be confused with adult mice at times. The tail of an adult roof rat is longer than its body. This is one characteristic that helps identify it as a roof rat and not a mouse. These rats also like to live in family units, so where there is one, there are most likely brothers, sisters, mom and dad plus an extended family. Roof rats are well adapted to take advantage of human habitation. They like houses, wood piles, sheds, landscape bushes, dense vegetation and all manner of fruits, berries, and nuts which they can use for food.
To address a roof rat infestation in a house or outbuilding, set traps using peanut butter and/or raisins as bait. Check and rebait traps frequently. Place the traps where you see signs of rat activity – droppings, nut shells, foot prints, etc. Also check the house for holes and cracks as small as one half inch in diameter through which roof rats can enter. Plug/cover these holes with steel wool or one quarter inch wire screen.
Next, dispose of fruit on the ground and clean up wood piles, brush piles, and other trash. Prune bushes and trees and dispose of the prunings. Prune bushes and trees away from your house to reduce opportunities for access. In other words, clean up your place with the idea of eliminating rat habitat.
Finally, do not expect this problem to go away overnight. It may take several months to a year or more to eliminate an established colony of roof rats.