mouse in seed pail

Mouse feasting in bucket of stored grass seed. P.Cooper photo.

Mice are seeking places to spend the winter and actively moving from outdoors to just about any protected area, including our homes, garages, shed and cars. They need shelter from the wet and cold weather like us and prefer to take advantage of areas humans have already created. Any dry and relative warm spot with access to food or an area to store scavenged food will do nicely. Car engines are another favorite nesting spot as they are sometimes warm and provide great protections from predators and weather. Mice will chew on wiring and filters under the hood causing considerable damage and cost for repairs.

House mice can live outdoors in good weather, but some will live in houses year round. They can have 8 litters of young per year with 5 to 6 babies each time. That is a lot of mice! Nests are usually made with 3o feet of a food source to keep the mother in close range with her young. Most often mice are active during the night.

mice in bird house must be evicted when old enough

Mouse family nesting in a birdhouse.

First line of defense to keep mice out of houses is to be preventive by sealing up or blocking points of entry. Seal cracks and crevices with spray foam around foundation where the sill plate attaches the frame of the home. Make sure doors and windows fit properly and use weather stripping. Mice can flatten their skeleton and cartilage to fit through a ¼ inch gap. They commonly squeeze through small gaps around wires and pipes entering the home. Mice are great climbers of trees and sides of buildings to gain access to attics and wall spaces. Trim overhanging tree branches, and prune back foundation planting from touching the house. Keep grass, brush and vegetation away from foundation. Inside the home, eliminate clutter which serves as hiding spots and nesting material. Attic and dryer vents can be covered with hardware cloth and caulk the edges.

Eliminate food sources for mice. If you are feeding the birds, you are also feeding the mice. Spilled seed on the ground attracts mice and other animals closer to the house. Cat and dog food left out all day in a dish for on demand feeding for your pet offers mice an anytime buffet, too. Store dry animal food, including dog biscuits in a hard, metal container.  Mice can chew through very hard plastic containers with their gnawing teeth.

Repellents are available which claim to keep mice away. One type emits a high-frequency sound humans are not likely to detect but animals do not like. Caution should be used as pets may not like either. Some versions are made for use under car hoods to keep mice out of engines. Scented mouse repellents are available containing various mixtures of peppermint, cloves, hot pepper capsaicin. Planting mint around the foundation is reported to work as a deterrent. Some folks claim mothballs will repel mice, but this is not a legal use of the product, and in practice mice have been known to relocate the stinky orbs out of their area.

Mouse control will be needed if your find activity or signs of mice inside the home. Sometimes you can hear them chewing on the wooden structure making up the house. Finding the tell-tale black droppings which look like a small grain of rice, only black, is means for action in that area.

mouse trap

Mouse trap places with the snap end against wall.

Control options are traps or poisons. Traps should be placed where you find the droppings. Mice prefer to run along the edge of the wall rather than out on the open floor. Place set traps butted up against a wall. Peanut butter is a great bait to use to attract them to the trap. There are many different traps on the market from the old-fashioned wooden base snap traps to battery operated traps with a metal plate which electrocutes the mice. I saw a new one which uses a funnel system and extremely small and strong rubber bands which snaps over their head causing a quick a death. There are also humane live traps where the mouse enters, the door closes behind it, and then you take the trap and mouse outside to release it still alive, just take it far away from your house.

Poisons are rodenticides regulated by the federal government. Always read and follow label directions. Mouse poisons can affect other non-target animals by directly eating the poison, or up the food chain if another animal or bird eats a mouse that ate the poison.  Also mice do not always leave the building after ingesting the poison, sometimes dying in the walls creating an odor as they decompose in an inaccessible site. Insects can find the carcass to assist in the decomposition process which brings another problem of bugs or flies into the home. Once the dead animal is completely decomposed, odor and insects should go away.

-Carol Quish