A mouse (plural: mice) is a small mammal belonging to the order of rodents, characteristically having a pointed snout, small rounded ears, a body-length scaly tail and a high breeding rate. The best known mouse species is the common house mouse (Mus musculus). It is also a popular pet. In some places, certain kinds of field mice are also common. They are known to invade homes for food and occasionally shelter.

The American white-footed mouse (Peromyscus leucopus) and the deer mouse (Peromyscus maniculatus), as well as other common species of mouse-like rodents around the world, also sometimes live in houses. These, however, are in other genera.

Cats, wild dogs, foxes, birds of prey, snakes and even certain kinds of arthropods have been known to prey heavily upon mice. Nevertheless, because of its remarkable adaptability to almost any environment, the mouse is one of the most successful mammalian genera living on Earth today.