House Mouse

In Alberta, we have seven unique species of mice and 12 species of voles.^[1]https://www.alberta.ca/other-mammalian-nuisances.aspx The most troublesome and economically important of the species found in Alberta are the house mouse, the white-footed mouse (deer mouse) and the meadow vole (field mouse).^[2]https://www1.agric.gov.ab.ca/$department/deptdocs.nsf/all/agdex594/$file/683.pdf?OpenElement Mice can often be fixed and prevented quite inexpensively, however more often than not mice go undetected in homes, which increases the amount of damage they can do. Mice will ruin appliances, chew electrical wiring, spread diseases to humans and pets, contaminate food, destroy clothing and much more. Mice will breed rapidly, with a female house mouse giving birth a half dozen babies every three weeks.^[3]https://www.pestworld.org/pest-guide/rodents/house-mice/

Identification

House mice are typically grayish-brown with cream-coloured bellies. They have a slightly pointed nose; relatively small feet; small, black eyes; large, sparsely-haired ears; and a nearly hairless tail roughly the same length as its body. Adults weigh 10-30g and measure 65 to 90mm (2½ to 3¾ in.) in total body length, including the tail.^[4]https://www1.agric.gov.ab.ca/$department/deptdocs.nsf/all/agdex594/$file/683.pdf?OpenElement

Risks

Mice pose 2 main risk factors for homeowners and their inhabitants: health risks and structural damage risks. Mice can spread deadly diseases to humans and pets by contaminating the homes they enter, while also chewing electrical wires, getting into vehicles, and causing fires. Your home insurance policy most likely will not cover damage caused by mice or any other vermin. This is a standard exclusion found in virtually any home insurance policy available in Canada.^[5]https://www.squareone.ca/resource-centres/insurance-basics/mice-damage

Signs of Infestation

1. Gnaw marks: Gnaw marks may be either rough or smooth. 
2. Droppings: House mouse droppings may be either soft and moist or dried and hard. The droppings measure about 3-6mm (¼ to ⅛ in.) long. They are rod shaped and pointed on the ends. 
3. Tracks: House mice leave 4-toed prints with their front feet and 5-toed prints with their hind feet. 
4. Rub marks: House mice often leave oily rub marks on walls, vents, and entry points where they came in. 
5. Burrows: House mice burrow using nesting materials such as insulation, often leaving traces of insulation debris. 
6. Runways: House mice usually use the same pathways. Active runways are sometimes visible, with rub marks, droppings, and footprints along them. 
7. Odor: The odor of house mouse urine may become distinct if there is a large number of house mice in a particular area, however it is unlikely you will smell this until the problem becomes quite severe. House mice use their strong-smelling urine to communicate with one another. 
8. Damaged goods: Mice prefer seeds or cereals but will eat pretty much anything they can find and access, including chewing through packaging and containers. 
9. Rodent sighting: If you see a mouse scurrying across the kitchen floor, there is likely a family of mice hiding out of sight.^[6]https://www.pestworld.org/pest-guide/rodents/house-mice/

Elimination

Disclaimer: Oftentimes mice can be treated effectively with products available over the counter, however there are 2 risks I must mention if you are considering a do-it-yourself (DIY) treatment. The first risk is safety. You will be handling poisons and dead rodents, both of which can be deadly to yourself, kids and pets if not handled properly. The second risk is non-solution. As I have mentioned before, over 82% of homes have traces of mice, while less than 12% of homes reported seeing rodents of any sort. This means that more than 70% of the time, mice go undetected. Oftentimes people will do treatment themselves, stop catching or seeing mice, and then discontinue treatment assuming the problem is resolved, when in fact it is not. Just because you don’t see mice doesn’t mean you don’t have mice. 

If it is within your budget, you will very likely save money in the long run by simply having a professional come out and correctly solve your mouse problem. In most cases, especially when treated early on in their infestation, mice are a relatively simple pest to eliminate for a professional exterminator. It often costs a lot less than you would expect to have the problem quickly and effectively eliminated by a professional. If you have seen mice inside, we encourage homeowners to contact a professional for a quote before going ahead with DIY remedies. 

Prevention

1. Seal off entry points: Mice can squeeze through a small, 6-7mm hole.^[7]https://sssb.se/en/wp-content/uploads/sites/2/Facts_ratsmice_ENG.pdf For reference, a standard #2 yellow pencil has a diameter of 7mm,^[8]https://en.wikipedia.org/wiki/Pencil while a Canadian dime has a diameter of 18mm.^[9]https://en.wikipedia.org/wiki/Dime_(Canadian_coin) A key component of any effective rodent prevention program is to identify and eliminate as many potential entry points as possible. This includes repairing weather stripping, garage door seals, door sweeps, cracks in the foundation or exterior, window screens, dryer vents, attic vents, soffits and more. 
2. Control vegetation around the home: You should cut back tall grass, weeds, and other greenery away from the house as much as possible. If you have lots of dense vegetation, such as juniper bushes and tall natural grasses on or around your property then we highly recommend having some form of exterior rodent control program on your property as you are at very high risk for rodent entry.
3. Secure garbage in containers: The garbage we produce in our home is a fantastic food source for mice, as they are able to find all kinds of scraps and food waste to survive on. Securing your garbage and food waste into bins with tightly fitting lids (mice are excellent climbers) will help eliminate food sources on your property and send mice away from your property in search of food. 
4. Sanitation in food handling areas: You should keep dry goods in metal or glass containers, as mice can easily chew through plastic containers and bags. You should also properly dispose of food scraps as quickly as possible. General cleanliness in your kitchen can be a great deterrent for mice.

Habitat

House mice tend to live in areas that allow total concealment away from humans and predators. Outdoors, mice will hide in underbrush or other dense vegetation, such as long grass, shrubs, and bushes. Mice tend to live in close proximity to humans and often hide in homes, businesses, factories, warehouses and other structures like sheds or barns.^[10]https://www.orkincanada.ca/pests/rodents/mice/ 

Diet

Mice survive on an omnivorous diet. They prefer to eat fruits, seeds and grains, however the house mouse will eat just about anything it can find. If food becomes scarce, mice will even eat each other. Mice will typically feed 15 to 20 times per day, so they build their homes in close proximity to food sources.^[11]https://www.livescience.com/28028-mice.html

Lifecycle & Reproduction

The gestation period for a female house mouse is about 19 to 21 days, and they give birth to a litter of 3 to 14 young (average 6 to 8). One female can have 5 to 10 litters per year, so the mouse population can increase very quickly. Breeding occurs throughout the year. Mice can begin breeding as early as five weeks.^[12]https://en.wikipedia.org/wiki/House_mouse#Life_cycle_and_reproduction

Due to numerous predators and exposure to harsh environments, mice will often live less than one year in the wild. In protected environments, however, they often live two to three years.^[13]https://en.wikipedia.org/wiki/House_mouse#Life_cycle_and_reproduction