What animal can be found in almost every state, and in northern Canada to southern Mexico?

A Deer Mouse

The deer mouse occurs as part of essentially all communities in North America below the treeline (high mountainous areas where trees do not grow). It has the broadest distribution of any species within the genus.   

Photo by David Cappaert, Michigan State University, Bugwood.org


You may not see it in the wild very often. Why? Because it is active at night and a rather small mouse-like rodent.

You may however, see it in a research lab. Deer mice are used because they are easy to care for and keep themselves clean.

This mouse is only three to four inches full grown with a multicolored tail that may be four to five inches long. The colorings, tail length, and markings vary widely with the soft fur color ranging from brown to black. The white underside and feet are consistent. The mouse got the name “deer” because its color pattern was similar to that of a white-tailed deer.


During the day the species spends a lot of time in trees a common nest location. They are excellent climbers and swimmers. They will also build soil burrows, use rock crevices, and a variety of other locations for their nests.

Nests are created using grasses, roots, mosses, wool, thistledown, etc.  They are often communal. Deer mouse litters are kept in separate, away from the communal nest.

These mice often stay in their original home range to reproduce. They are social, and will recognize and interact with mice that have overlapping ranges. Communications are chemical, visual, and vocal (such as shrieks, squeaks, trills, and drumming out a warning.

OCD-like Behavior

Movement is usually on foot walking or running. They will also leap when threatened. Limited movement leads to intrafamilial mating and limited gene flow within a range.

This may contribute to OCD-like behaviors that become evident by two months old. One behavior is creating overly large nests in the lab when not necessary.


This rodent reproduces profusely compared to other species and even to local mammals. Food availability, rather than season, will determined breeding opportunities.

It is not uncommon for female deer mice to have three or more litters per year. Captive deer mice have had as many as 14 litters in one year.

Mice reach adulthood at six weeks.


Deer mice are omnivores and will change their eating habits based on the season. This rodent heavily consumes arthropods such as spiders and caterpillars in the winter with seeds, insects in the spring, seeds, fruits, and leaves in the summer. They will also consume fungi.

Deer mice hoard their food and will store up to one pint of food in ground holes, tree cavities, and nests.


They are prey for almost everything like larger mammals, snakes, domestic pets, and birds. Deer mice are can carry viruses.

Disease Carrier

One particular virus to note is the Hanta. These rodents can carry the airborne hantavirus. Hanta can be passed to humans during clean up operations and through contaminated food.

Minimize the Risk

To minimize these rodents minimize potential nesting locations such as rock piles, firewood, and vegetation (especially vines connecting trees to attics) before cold weather hits. Close up any openings to your home. Get some help eradicating an infection.      

–Oregon Dept. of Fish and Wildlife, Deer Mouse (https://myodfw.com/wildlife-viewing/species/deer-mouse)
–USDA Forest Service, Fire Effects Information System (FEIS) (https://www.fs.fed.us/database/feis/animals/mammal/pema/all.html)
–(Wikipedia, Peromyscus maniculatus (https://en.wikipedia.org/wiki/Peromyscus_maniculatus)
–Orkin, Deer Mice (https://www.orkin.com/rodents/mouse-control/deer-mice)
–Animalia, Deer Mouse (http://animalia.bio/deer-mouse)