A mouse is a small rodent with a pointed nose, furry round body, large ears and a long, often hairless, tail. There are hundreds of types of mice, divided into subfamilies of either Old World or New World species. Common varieties include deer mouse, house mouse, field mouse, wood mouse, dormouse, spiny mouse and zebra mouse.

Though some people talk about mice and rats as if they were the same thing, they are actually different types of animals in the rodent family. Rats generally are larger than mice, and they can be bald, scaly and cylinder-shaped.