The house mouse has large ears and is light brown to dark grey, with a lighter colour on its belly. It is often found in urban areas. The deer mouse is brown or grey with a white belly and feet. The white colour on the underside of its tail is an easy way to spot a deer mouse. It may invade buildings near fields and woodlands in the fall.
A rat is larger than a mouse and can weigh up to 0.5 kilograms (1 pound). The Norway rat and the roof rat look similar, but their habits are different. The Norway rat builds elaborate systems of tunnels and burrows at ground level. It prefers damp areas like crawl spaces or building perimeters. The roof rat is an agile climber and prefers to live in trees, vines, and other dense vegetation. It will infest attics, rafters, or roofs, and upper stories of buildings.
Knowing the type of pest you have can help you figure out the best approach to controlling them. (For example, a rat trap is too large to kill a mouse.)