The house mouse has short hind feet and a tail that's as long as the head and body together. They’re usually a dark grey, but some house mice have light-brown backs with light-brown bellies. When fully grown, they weigh about 15 grams (0.5 oz.) and are 8 cm (3 in.) long.
Females have 6 to 10 litters a year. They have about 5 babies per litter. The house mouse lives for about 1 year.
How do they get into a home?
The house mouse usually enters a home in the fall and winter looking for food and shelter. They enter through holes or gaps in doors, walls, and foundations. A house mouse can squeeze through a crack as small as 1 cm (smaller than a dime).
You often realize that you have a house mouse because you see droppings (poop) near food, under stoves, refrigerators, and under sinks. You may also find holes in boxes and bags that have food or garbage in them.
What problems to they cause?
Mice cause damage by gnawing on insulation and building material, furniture, paper, clothing, and books. They contaminate (put germs on) food with their urine, hair, and droppings. Food can become contaminated with germs like salmonella. Mice also carry fleas, mites, and the disease hantavirus.
How do I control them at home?
The best way to control a mouse infestation is with integrated pest management, which means using many methods at the same time. This includes:
- physical methods like traps
- chemical methods like poison
You can also call a licensed pest control operator, especially if the infestation is bad.
Keeping your house clean will help prevent mice from moving into your home. Once you know you have a house mouse, make sure to protect all food. Use glass or metal containers because mice can chew through plastic.
Mouse proof your home by using steel wool to seal openings and holes in and around:
- anywhere else mice could get in
How do I catch the mice?
Trapping is best when it's not safe to use poison baits. Don’t use poison baits around food, children, or pets.
There are several types of mechanical devices you can use to catch mice. Snap traps work well, causing an instant death. Make sure you bait and set the trap properly. Dried fruit, peanut butter, or marshmallows work very well as baits.
Another trap that works well is the ready-to-use glue board. When mice try to cross the board they become glued to the surface and eventually die. Glue boards are scented or can be baited (such as with peanut butter).
You can buy both types of devices in hardware stores. Put the glue boards and snap traps in corners and across the paths that mice use (mice prefer to travel around the edge of a room). Make sure you check them often.
If the traps don’t work, you might have to use poison bait. Most ready-to-use commercial baits have a product in them that damages the mouse’s blood vessels and doesn’t allow the blood to clot. The poison bait causes the mouse to dry up rather than rot. This means the dead mouse won’t smell.
Place poison baits where only mice can get them. Keep them out of reach of pets and children. Follow the directions carefully.
How do I handle a dead mouse or droppings?
Assume all mice carry disease. Do the following when you’re cleaning up a dead mouse or trap, droppings or urine, and nests:
- Open windows and doors for 30 minutes to air out the area.
- Wear a respirator with an N-100 filter. Drug stores and hardware stores sell these respirators.
- Don’t dry sweep or vacuum the droppings and nesting material so that you don’t create any spray.
Follow these steps to clean up after dead mice, nesting material, and droppings:
- Soak the mouse, nesting material, and droppings with a disinfectant or household bleach solution (1.5 cups of bleach per gallon of water or 1 part bleach to 10 parts water).
- Clean up the area with a wet paper towel. Use latex or rubber gloves or use a plastic bag as a glove when cleaning up or handling any items.
- Put the dead and trapped mice, nesting material, droppings, and cleaning material in a sealed plastic bag and put it in a garbage container outside. Before you take off the gloves, wash your gloved hands in the bleach solution.
If you’re using a pesticide (poison), read the label closely. This method works best when you also use physical control methods like traps.
When should I hire a professional?
If the problem is bad, it’s best to hire a certified pest control professional. Do your research and choose one you can trust.
The professional should be able to tell you what’s causing the pest problem and come up with a plan to get rid of the pest. The professional may need to make several visits, and it may take days or even weeks. Tell the professional if you have children or pets.
If you rent, your landlord must, by law, keep the home pest-free and hire a professional as needed. If your landlord doesn’t correct the problem, call Health Link at 811 to register a complaint for a health inspector.
To learn more, contact Alberta Health Services Environmental Public Health.