Deer mice are nocturnal animals that find food during the day. They are omnivores, generally eating whatever food is available, including berries, fruits, nuts, seeds, insects, and whatever they can find that looks good.They do not hibernate, instead remaining active throughout the winter. They do, however, stockpile some food during the warmer months in their nests to make foraging easier during colder times. There is no one breeding season for deer mice, instead they produce litters around once a month. They have the most extensive range of any North American rodent.