Everett
During cooler autumn weather, crops of corn and soybeans will soon be harvested. The open fields will allow house mice (Mus musculus) to become easy targets for their natural predators which include cats, foxes, hawks, and owls. House mice will burrow, run, and try to escape these predators, and, at the same time, seek a protected place to spend the winter. Protected places to spend the winter may include your home, shed, garage, and any other building that will offer protection. House mice can enter buildings with openings as small as a quarter inch. Often overlooked areas are where utilities enter and exit the structure such as power and gas lines, cable, and satellite lines, as well as water and sanitary sewer lines where caulking may be absent or have come loose.
House mice are small rodents with relatively large ears and small, beady black eyes. They weigh about 1/2 ounce and usually are light brownish to gray. An adult body is about 2-3 inches long, moreover, the tail adds another 3-4 inches. The most obvious indicators of their presence are droppings or feces that are 1/8 – 1/2-inches long, dark and pointed at both ends. Sometimes you may hear sounds of these mice running, gnawing, or squeaking.
Did you know house mice are not picky eaters? House mice like your dog’s and cat’s food and, of course, human food especially if it is high in fat and protein such as such as nuts, bacon, butter, and sweets. They also eat many kinds of plant matter, including leaves, stems, seeds including bird seed. House mice will also eat beetles, caterpillars, cockroaches, and other insects. Interestingly, house mice have been known to feed on book bindings that contain glue, along with the leather covers.
The greatest economic loss from house mice is not due to how much they eat, but what must be thrown out because of damage or contamination. Food, clothing, furniture, books, and many other household items are contaminated by their droppings and urine, or damaged by their gnawing. House mice gnaw through electrical wiring, causing fires and failure of freezers, clothes dryers, and other appliances. House mice also can transmit diseases, most notably salmonellosis (bacterial food poisoning) when food is contaminated with infected feces.
House mice once inside a building, can be difficult to control. Part of the reason is house mice are prolific breeders, producing 6-10 litters continuously throughout the year with each litter having between five to seven offspring. Another reason that house mice are mainly nocturnal and may not be seen unless there is an abundance of mice. They may be just as comfortable living behind the kitchen stove as living in wall voids or the ceiling.
Control tactics include exclusion, sanitation, mouse baits otherwise known as rodenticides, mouse traps, and glue boards. Elimination is easier said than done especially if you live in an older home. Start by caulking all outdoor utility entryways. Inside the home steel wool pressed into water and drainage pipe openings works well. Also, check around windows and foundation areas to make sure they are as tight as possible.
Elimination in garages, sheds, and other outbuildings may be exceedingly difficult. This is where strict sanitation comes in. I keep kibble dog food in the freezer out in our shed; then I refill the dog food canister periodically from that location. One time when refilling it I dropped some kibble behind the freezer and did not clean it up. House mice found the kibble and some fiberglass batting making a nest inside my lawn tractor. When spring came and it was time to mow, I had a heck of a mess. I spent countless hours cleaning out the mower and areas behind the freezer. Lucky for me the house mice did not chew through any wires.
Garages are sometimes used for entertaining. Make sure you clean thoroughly after any events. Inside the home, keep the kitchen and any food storage areas clean. Remember to clean behind your larger appliances.
Even with exclusion and sanitation, other control methods must be utilized. A myth is house cats will keep house mice at bay. On another occasion in the evening our cat and two dogs besides myself and wife watched a house mouse scurry past us in the living room. Of course, the cat and dogs were either oblivious or chose to ignore the whole situation. Now this called for the big weapons: mouse traps.
Mouse baits or rodenticides for home use contain some type of anticoagulants or blood thinners. These baits normally are of a grain type impregnated with a toxin. When house mice feed upon them they die of internal bleeding. They do not die right away, and if they are residing in a wall void, nothing is more unpleasant than a decaying mouse smell. The other problem with mouse baits is they may be attractive to children and pets.
Placing mouse traps or snap traps baited with bacon or peanut butter and placed near where you find house mouse droppings works extremely well. The downside of this method is that you need to dispose of the dead mouse preferably while wearing gloves cleaning the trap and resetting. Keep trapping until there is no more mouse activity. This may take a few weeks.
Another trapping method is using glue boards. Mice become entangled in the glue when they run over the boards, soon dying of suffocation. The downside is once they are trapped you need to replace with a new glue board.
House mice have interacted with humans and our shelters long before any Europeans settled here. They have adapted to our lifestyle. They are also a reliable food source for many predators. We ought to adapt to the house mice and think like a mouse so we can live happily ever after.
The author acknowledges the University of Michigan BioKIDS a partnership of the University of Michigan School of Education, University of Michigan Museum of Zoology, and the Detroit Public Schools and the University of Kentucky Department of Entomology for contributing information for this article.
