The desert pocket mouse, Chaetodipus penicillatus, occurs in the southwestern United States and much of Mexico. In Utah, the species occurs only in the southwestern corner of the state. The preferred habitat of the desert pocket mouse is sandy desert with sparse vegetation. The species is nocturnal, and individuals may hibernate during part of the winter. Inactive periods are spent in underground burrows.
Females may give birth to one or more litters of two to five young during the spring and summer of each year. Desert pocket mice primarily eat seeds. Similar to other pocket mouse species, the desert pocket mouse has external fur-lined cheek pouches used for temporary food storage. Long-term seed storage occurs in underground burrows.