Northland Nature: Deer mice invade human homes in November
November is a good time to get acquainted with many of the local wild mammals. Deer are obvious at this time, but many other critters are seen or heard now, too, as they respond to the colder and shorter days of this month. Seeking late fall meal...
November is a good time to get acquainted with many of the local wild mammals. Deer are obvious at this time, but many other critters are seen or heard now, too, as they respond to the colder and shorter days of this month. Seeking late fall meals, raccoons, bears, skunks and foxes may visit our yards during these long nights. And at this time, we are more likely to hear the calls from coyotes in the open fields, while flying squirrels squeak from nearby trees. Snowshoe hare that have already donned their white winter coats now stand out in the drab woods. Squirrels are busy caching meals or coming to feeders for free handouts. Out on the swamps and lakes, otters try sliding on newly-formed ice, while beavers make their last provisions as the surface freezes.
But maybe the most common mammals at this time are the mice. Mice of several species have been with us throughout the year, but now as the chill moves in (which coincides with their population peak), they seek a warmer place to spend the winter. Too often this site happens to be our site as well.
Native mice in the Northland may be best told apart by the length of their tails. Short tails are on the lemmings and voles (including field mice). Middle-sized tails, about equal to the body's length, are on the deer or white-footed mice. And long tails, much longer than their body (maybe twice as long), belong to the jumping mice. The last of these, the jumping mice, have huge hind legs and are well named for their leaping abilities. Since they tend to be early and deep hibernators, we are not likely to have them move in. Lemmings and voles also are more at home in bogs, swamps and fields. The deer mice and white-footed mice will, however, be glad to live in human-made dwellings.
Both kinds have large eyes and ears as expected for a nocturnal life. They have a brown back and light undersides on the 4-inch body. Deer mice tend to have longer tails. They are residents of the boreal forests. The slightly shorter white-footed mice are more common in the deciduous woods. Both are agile climbers and can be found living in nearly any growth of trees. As omnivores, they feed on nuts, seeds, buds, berries, insects and carrion. Such a varied diet accounts for their abundant status.
Though they take to the trees well, dens are usually on the ground. However, if an abandoned squirrel's nest or bird house is discovered, they will move in. In our houses, garages, outbuildings or cabins, they readily make themselves at home. Many a home owner has discovered their telltale chewings and droppings as these small rodents adjust to this dwelling.
European house mice are pests in urban areas throughout the country, but in the Northland rural settings, deer mice and white-footed mice are the traditional guests, albeit uninvited. During this month of November, the influx of these big-eyed mice is as regular of an event as the first snowfall or freeze-up. It may not be consoling, but we can be sure that if we see such residents in our homes, we are not alone.
Larry Weber is author of the "Backyard Almanac." He lives in Carlton County and teaches natural science at Duluth's Marshall School.