It's called Mus domesticus for a reason: While it can survive outdoors, it prefers a roof overhead, especially when the weather's cold. Once inside, these naturally curious creatures like to poke about at night, cruising for carbs and opportunities to hook up. Big ears, tiny paws, and long whiskers may make these mice Beatrix Potter-cute, but they can spread salmonella as they scamper, chew electrical wires, and keep you awake with their infernal nightlife. Had it with these sticky-fingered houseguests? Familiarize yourself with their MO.
Males battle it out for real estate and stake claims by spreading around their allergy-inducing urine; a boss mouse on a tear is basically incontinent. House mice prefer to stray no more than 30 feet from their comfy nests, though they will travel up to 75 feet when their shelters are disrupted or they're compelled to forage for food and lodging.
They eat like birds
Mice evolved on seeds and grain, but these days they are happy having what you're having. And only about 4 grams a day—nibble, nibble, nibble. No need for running water: The moisture in edible debris can suffice.
They have muscles
Mice can climb, jump, swim, squeeze through tiny cracks and holes, and survive long falls. They like to chew on wood, plastic, and—to the alarm of whiskers to navigate, along with impressive muscle memory ("If the baseboard is on my right as I enter, it will be on my left as a exit—duh!").
Mice use their keen noses to pick up on pheromones and determine the age and gender of likely mates. Dominant males mate early and often; females can produce litters of six or so wee ones every couple of months. Mice burn their candles at both ends because life is short—about 18 months.
It's a love-hate thing with cats
Sure, cats enjoy batting mice around like pinballs. But a well-fed feline also naps a lot. When a mouse finds a food bowl big enough for a crowd—and the guard's sleeping on duty—it'll dive right in.
Say Good Riddance
Trim foliage within 18 inches of the foundation, and inspect your exterior for ¼-inch and larger holes and cracks. Same goes for indoors. Pack voids, plus gaps around pipes and utility lines, with silicone or polyurethane sealant that stretches with temperature changes. Fill larger holes with coarse steel wool or fine metal mesh and flexible sealant. Screen exhaust vents. Weatherstrip doors and windows; don't forget the garage.
Find out where they nest: Use a flashlight to track droppings or dust the floor with talc for footprints. Set snap traps in pairs; a suspicious mouse may halt if it senses something in its path and leap over trap 1, only to land on trap 2. Place the bait end against the baseboard. Mice go nuts for bacon, peanut butter, chocolate—and cotton balls, which make comfy bedding.
Put out poisoned bait
The trick is to place it in the path of hungry mice but away from curious kids and pets.
Dispose of your catch with rubber gloves, and disinfect the area with a weak solution of bleach and water. All this killing, cleaning, and safety concern give you pause? Consider hiring an exterminator.