A deer mouse is a small rodent, recognized by its distinctive coloration and physical features. It typically has a bi-coloured appearance, with a brown or greyish-brown back and a white belly and feet, reminiscent of the colouring of a deer, which contributes to its name. Deer mice have large, black eyes and big ears relative to their head size, giving them a characteristic alert and delicate appearance. They possess a pointed snout and long whiskers, aiding their sensory navigation. One of the most distinctive features of the deer mouse is its tail, which is usually long, sometimes as long as the body, and bi-coloured—dark on top and white underneath. Adult deer mice can range in body length from 7 to 10 cm (2.8 to 3.9 inches), with the tail adding 5 to 13 cm (2 to 5 inches) in length.