Food, water, shelter—of the three pillars of survival, the latter becomes particularly important as cooler weather rolls in, and the scurry from outdoors to indoors intensifies.
Just like humans, mice are starting to look for a safe place to call home, preferably one with free heat and plenty of snacks. Who could blame them?
Yet mice can pose serious health risks to humans, as well as causing house fires and ruining appliances when they chew on electrical wires. In addition, Cornell Cooperative Extension notes, “their urine, musky odor, and gnawing can ruin food, clothing, papers, woodwork, insulation and plumbing.”
One cookie left behind a couch cushion can feed a mouse for more than a week, according to the Utah State University Extension. Because they’re most active at night, mice can roam around a house undetected, and a single one seen could mean the presence of at least several others. A pair can produce several litters—with ample food, of 10 to 12 mice each. Those litters can begin reproducing within two months.
Eek.
“The best control method is to prevent them from getting in,” the Utah extension notes.
“In the colder months, mice are seeking warmth, just like anybody else,” said Dell Cullum, owner of Hampton Wildlife Removal and a local nature photographer and naturalist. “Chances are, that warmth is coming from your home.”
Mice typically enter through the foundation, he said, contrary to the popular idea that they get in through the attic or chimney. Mr. Cullum said mice can squeeze through any hole larger than the width of a pinky, so it’s important to check around the foundation for possible entry points. “They live along the sill plates where the house sits under the foundation,” he said. “That’s typically where you would find them.”
From there, the critters may travel along wires and pipes in the basement until they make their way inside a home. “They’ll usually end up in a bathroom or under a kitchen sink, because that’s where the pipes will lead them,” Mr. Cullum said.
For their nests, mice favor undisturbed spots like wall cavities, attics, garages and basements, according to Cornell, as well as places close to food in and under cabinets and kitchen appliances, or in stored clothing or bedding. They line their nests, which are about 5 inches in diameter, with materials like shredded cloth or paper.
If they get inside they’ll leave clues: small, dark pellet-like droppings, which must be handled with care to avoid contamination. Cornell recommends wearing rubber gloves and a face mask when cleaning up droppings, urine or nests as well as ventilating the area and avoiding stirring up dust, which could contain hantavirus, by sweeping or vacuuming. Instead, a bleach solution or household disinfectant should be used with a sponge; more information can be found at http://www.nysipm.cornell.edu/publications/evictmice/intro.asp.
Mr. Cullum said the number of visitors can easily be determined by the quantity of droppings. Other clues, according to the Cornell and Utah extensions are the musky smell of urine coming from cupboards or drawers, gnaw marks, shavings, burrow holes and track marks or smudges, often near or along wall.
“Mice have poor eyesight, so they tend to hug the walls during travel,” Cornell says. “They memorize routes between food and nest and rarely stray; this helps them run rapidly along a path, even in the dark.
“In time, a faint, dark ‘trail’ of body oil and dirt may become visible on woodwork. In dirt or insulation, you may see a smooth, worn path. Shine a strong flashlight at a low angle across a dusty area to look for footprints.”
Noise is another clue, Cornell notes. “You may hear scuttling, squeaking, or gnawing inside the walls, especially at night. Other animals make similar noises, so this is not a definitive sign of rodent infestation. House pets may be disturbed by sounds of rodent activity that you cannot hear.”
Keeping house cats is a relatively easy and humane way to keep mice out, Mr. Cullum said. While cats are by nature hunters, their presence alone can be enough to deter mice, and the cats’ own musk also acts as a deterrent.
“Everyone I know that has cats rarely has rodent problems,” Mr. Cullum said. “Some cats have that attitude, they don’t care and they’ll just watch a mouse go by, but for the most part it works.”
If droppings are not immediately apparent, Mr. Cullum said signs of mice might be found inside exposed insulation in a basement ceiling, which might sag or begin to fall from the ceiling because of feces and nests.
“Don’t ignore that,” he said—and don’t vacuum up any of the droppings, he stressed. “Always wear gloves and a respirator mask” for such projects, he advised, adding that in severe situations, it is safer to consult a professional. Where possible, he also recommended replacing foam insulation with a foam insulation spray before problems occur.
If mice need to be exterminated, traditional snap traps are always preferential to traps with poison, Mr. Cullum said. According to the University of Georgia, traps should be placed along the wall “with the bait treadle across his path at a right angle to the wall.” It is important to set the trap perpendicular to the wall so mice don’t have to travel over the trap to reach the bait. To lure mice in, the university suggests using “anything with a strong odor,” like peanut butter or bacon.
Humane traps are also an option, said Mr. Cullum, and work especially well when one suspects that there are only one or two mice in the house. “Then you can take them out of the trap and put them back in the woods,” he said.
As for ultrasound devices that plug into the wall that emit a frequency to deter mice, Mr. Cullum said he believes they aren’t all they’re cracked up to be. “I’m not saying my answer is right or wrong, but in the past, I’ve found that mice quickly become immune to them,” he said. “They’ll work great until the animal faces them two or three times, like everything else, and adopts to it.”
At the end of the day, Mr. Cullum said, no one is immune to problems with mice.
“Everyone gets mice,” he said. “Whether you live in a mansion on Further Lane, or a more humble abode elsewhere, it can happen to anybody.”
on Oct 4, 2014