Differences Between Rats and Mice

House mice measure 12 to 20 cm in length, including the tail, and weigh 12 to 30 grams. They may be white, brown or grey in color. Their snouts are triangular and feature long whiskers. Mice have large, floppy ears and long, thin, hairy tails. These rodents can be found throughout the world in a variety of climates and environments. They can live up to six years in captivity though most naturally live less than a year. Mice are nocturnal, timid, social and territorial in nature.

Rats are medium-sized to large rodents with long tails that are commonly hairless and scaly. Like mice, these rodents are also found throughout the world, in varying environments. They are also nocturnal in nature. However, rats may grow to be as long as 40 cm or more and weigh considerably more than mice. Their coats are white, gray, brown or black in color and are often soiled enough to leave grease marks on touched surfaces. The snout of the rat is more blunt than that of the mouse.