A mouse is a small rodent with soft fur, round ears, a pointed nose, and a long tail. Mice scurry quickly on four legs and can squeeze through surprisingly tiny spaces. They eat seeds, grains, and just about anything else they can find, which is why they sometimes sneak into houses looking for crumbs. In the wild, mice live in fields, forests, and grasslands, building nests in hidden spots. Some people keep specially bred mice as pets because they're intelligent and surprisingly social animals.

The word also refers to a computer device you move with your hand to control a pointer on the screen. You click the buttons on a mouse to select things, open programs, or play games. Modern wireless mice connect without cords, and laptop trackpads do the same job by sensing your finger movements. The plural is usually mice.

Being as quiet as a mouse means making almost no sound at all, since mice move so silently when they're trying not to be noticed.