Cactus mouse

Latin Name
Peromyscus eremicus




Cactus mice, averaging 3 inches in body length, live in burrows or rock crevices in their native desert habitat. These quick, agile climbers are noctural omnivores, foraging for seeds, insects and vegetation at night, while lowering their metabolism during the day to cope with extreme temperatures.



Desert areas of southwestern United States, northern Mexico and several nearby islands


The species is common throughout its range.


Cactus mice are restricted almost entirely to a desert habitat, especially where rocky outcrops or cliffs provide retreats and den sites.


Their food is largely seeds of various desert annuals, mesquite beans, hackberry nutlets, insects and green vegetation. Succulent plants provide water in areas where rain is infrequent.

Life History

Breeding in cactus mice colonies occurs from January–October and sometimes year-round. Litter sizes average one–four offspring, and females may have up to four litters per year. Young cactus mice are born with ears and eyes closed but develop rapidly. The species' average life span is 1 year.

Special Adaptations

Cactus mice, like many desert mammals, aestivate when temperatures rise during the day: they lower their metabolism and enter a state of torpor that allows them to survive on very little water. They're also fast for their size and can scale rock walls and trees—a trait that helps them evade predators like owls and rattlesnakes.

Bonus Content

Mouse in the House
A desert rodent family warms up to its new home at the Regenstein Small Mammal-Reptile House.


Lincoln Park Zoo Exhibit