Deermice rarely leave their homes during the day, but feed opportunistically at night on whatever is available: seeds, nuts, fruit, berries, insects and other animal matter, and whatever they find tasty in houses. Deermice have the most extensive range of any North American rodent, and are found in almost every kind of habitat. They climb easily, tunnel through snow or scurry about on its surface, and find shelter everywhere from mattresses to tree cavities to burrows in the ground. Populations fluctuate in cycles of three to five years, sometimes correlated with the amount of food available. The Deermouse is important as a laboratory animal, and can be a factor in the spread of some human diseases, including hantavirus, plague, and Lyme disease.

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Mammal Species of the World