In Minnesota, there are 14 kinds of native mice and two introduced, or foreign, species.
Newcomers include the Norway (or barn) rat and the house mouse. These alien species have come to represent — or rather misrepresent — mice and rats in general. They have lived near humans since the dawn of man. Both are adaptable regarding habitat, eat almost everything, breed rapidly, and are notorious for damaging property. The rat is doubly dreaded because it so often carries disease. Worldwide, diseases spread by rats have killed more people than all of mankind's wars.
Of the 14 native species, the deer mouse and the white-footed mouse are the most handsome. They have long tails, large eyes and ears, pure white bellies and feet, with gray or brown upper parts. These mice are nocturnal, active in the winter, agile, hardy, and enjoy a miscellany of fare including all sorts of seeds, buds, small fruits and insects. They seldom damage crops. They are believed to be largely responsible for the disappearance of deer antlers shed in winter.
Food is stored in many areas within their territories, such as under logs or among rock crevices. And they nest almost everywhere: in ground burrows, tree holes, old bird nests and buildings. The territories of these mice are rarely more than a quarter-mile in diameter. Deer mice exist throughout Minnesota, while the white-foot is found everywhere except the northeast.
Jim Gilbert's Nature Notes are heard on WCCO Radio at 7:15 a.m. Sundays. His observations have been part of the Minnesota Weatherguide Environment Calendars since 1977, and he is the author of five books on nature in Minnesota. He taught and worked as a naturalist for 50 years.