Deer Mice (Peromyscus spp.) is the group name for a fair number of species of field mouse that, to the casual observer, all look alike. In general, they are small (bodies about 3-4 inches long and tails about the same length), with reddish backs and white bellies. Sometimes the group is referred to as "white-footed mice," which reflects the fact that most have white feet. Contrary to common opinion, these little creatures are quite cute with a big nose, big black eyes, and big ears, and long whiskers.

Experts tell these mice apart by such characteristics as the teeth, shape of the skull, the length of the hairs on the tip of the tail, the degree of contrast in the color of the upper and lower surfaces of the tail (black over, white under), and the length of the ears. Sometimes they can only be told apart by humans using DNA (the mice have no such problems).