Courtesy National Institute of General Medical Sciences
Watch out if you find a mouse in your farmhouse! Where there’s one house mouse, there’s likely to be several more.
We’ve always had a lot of mice on our farm—Mom calls our feed building Mousehaven—but this year they’re much worse than before. Uzzi and I crept indoors last night and booted up the computer so we could learn more about mice.
We discovered that most of our mice are house mice, a species called Mus musculus. You can tell them from other mice, like the deer mouse, cotton mouse and brush mouse, by their color: They are light brown to dark gray with no markings, and their bellies are lighter colored but never white. Adult house mice are 5½ to 7½ inches long, including a 3- to 4-inch tail, and they weigh a teensy 1/2 to 1 ounce. They are pretty cute with big ears; small, black eyes; and nearly hairless tails.
House mice are pretty amazing creatures. According to Michigan State University, they can jump 12 inches high from the floor to a flat surface or leap against a wall or another object to jump even higher. They don’t even need a trampoline! It’s easy for them to scamper up almost any vertical, rough-surfaced wall and run along electrical wiring, fencing or small ropes. You’d think they’d be worried about falling, but no. House mice can jump from 8 feet high without getting hurt. They’re also good swimmers, and they can squeeze through openings only slightly more than 1/4 inch in diameter!
If you have mice, watch out: You often have lots of them because mice breed year-round. Pregnant mama mice build 4-inch, loosely woven nests in warm, sheltered locations using shredded paper, cloth, insulation or the like. They can produce up to 10 litters of 5 or 6 babies in a single year. Newborn mice are tiny and completely helpless, with closed eyes and ears and very little hair. By the time they’re 2 weeks old, their eyes and ears are open and all their hair has grown in. At 3 weeks old, they begin leaving the nest to seek solid food. They’re sexually mature at 6 to 10 weeks of age.
Mice are an economic nuisance, not due to how much they eat but due to what must be thrown out because of damage or contamination. Mom gets mad when they invade the house and poop on things. House mice produce 50 to 70 black droppings a day and they aren’t picky about where they leave them.
House mice also invade the pantry, ours as well as Mom and Dad’s, and nibble mouse-size holes in bags of food. They prefer grain to other goodies but eat almost anything. House mice sit up on their haunches when eating a piece of grain, like an oat or a kernel of corn, and hold it in their paws, nibbling like humans eating corn on the cob. Other things they like include chocolate, peanut butter, dried fruit, bacon, cat food, slices of hotdog, beef jerky, cheese, breakfast cereal and nuts. People use these foods in traps to catch mice.
House mice may be cute, but they’re might destructive. Mom and Dad set humane traps to catch mice, then relocate them to an abandoned barn far from where people live. (The owner of the property said Mom and Dad could do this.) It helps, but there are always more mice where those came from.