Mice are a problematic species that infest human homes for a multitude of reasons. They may be looking for food but initially, their primary goal is a safe place to give birth. Mice are easy prey for birds of prey and other animals that want them for a snack so mice will tend to find places to hide and then can include your shed, your deck, your garage and your house. They may infest a location that doesn’t even have any food to be accessed because they can go outside and eat the seeds falling out of your bird feeder. What they need is a safe place to live and grow their family. Mice are quick to mate and give birth. They also grow very quickly. It takes only four weeks for a mother to come to term and they can have up to fourteen babies in a litter. This means you could have one mouse enter your home and within a few days, there will be fifteen. These babies will grow fur within one week, that’s all. Then a week later they will be adults, leaving the nest to make their own so they can mate and produce more babies. Mice have a genetic structure that does not get affected by inbreeding so the children can mate with each other and the result will just be more mice. Of course, there may be changes and some mice will die during birth but because they can produce so many at a time it will not change the fact that you will be overrun by mice. One of the easiest places a mouse can enter is the basement of a house.
This is because they are not native to this country and evolved to infest human homes over thousands of years in Europe. They were delivered to America on ships and have since been an invasive species in North America and other parts of the world. While Ontario does have wild mice, field mice and deer mice, these mice can live in the wild and can climb and jump great distances. House mice have lost those attributes and must enter homes through openings at ground level. The most common entryways they use are foundation gaps and weep vents in brick houses. Those are the mortarless holes between brickwork at the base of the house which allow the insulation in the walls to breathe. They can squeeze through just about any opening that is about the size of a quarter and this makes it very easy for them to get into a house. They also have incisor teeth that continue to grow throughout their lives which allows them to chew on hard materials like concrete essentially indefinitely. They will eventually make an opening and can hide in tall grass, bushes and gardens. That is why it’s important to keep gardens and plants away from the walls of the house and to keep your lawn as short as possible. This will give me less of an opportunity to get into your home as they will have nowhere to hide while they find an entryway.