White-footed mouse: A rodent capable of carrying the types of hantavirus that cause HPS (hantavirus pulmonary syndrome) in the US. The white-footed mouse is hard to distinguish from the deer mouse. The head and body together are about four inches long. Its tail is normally shorter than its body (about 2 to 4 inches long). Topside, its fur ranges from pale brown to reddish brown, while its underside and feet are white. The white-footed mouse is found through southern New England, the Mid-Atlantic and southern states, the midwestern and western states, and Mexico. It prefers wooded and brushy areas, although sometimes it will live in more open ground. Scientific name: Peromyscus leucopus.