The brush mouse, Peromyscus boylii, is a gray-brown mouse with a noticeably furry tail that occurs in the southwestern and south-central United States, as well as in parts of Mexico. The brush mouse is common in central and eastern Utah, occurring in areas containing rocks and heavy brush.
Brush mice eat nuts, berries, insects, and other arthropods. They are talented climbers, and often climb vegetation to forage. Mating occurs from late spring to early fall, and females can produce multiple litters of one to seven young each breeding season. Brush mice are nocturnal and active throughout the year. Nests are built in rock crevices or under thick brush.