If you saw the mouse at night, especially in places like the attic or a closet, you almost certainly have more than one. Mice are rarely active during the day, so this one was probably pressured into your home by weather or predators. If you saw the mouse during the day, and in a heavily trafficked area of your home (such as the kitchen), there’s a good chance it’s alone. It’s difficult to answer this with precision, because there’s just no way to tell how many mice you have without capturing or killing them all and counting. If you see one mouse how many do you have?
Having mice doesn’t mean your home is dirty, it just means they found a way in. Mice are far from the only animals that would love to take up residence in your house, but they’re one of the few species that’s small enough and adaptable enough to actually do it. Mice want the same things every animal wants: food, water, and shelter. Especially in the winter when houses are warmer and safer than the environment outside, mice are drawn to houses like a moth to flame. That means that mice tend to live in all the same places we do, and our homes are very attractive places for them. They breed quickly, can live in almost any climate, and they eat a lot of the same foods we do. Estimates vary, but some think that as many as 21 million homes are infested with mice every year in the United States. These are the most common questions about house mice. If you have questions about house mice, there’s a good chance someone else has already asked the same question.
Since they’re such common pests, people tend to have lots of questions about them. As their name suggests, they’re extremely common in our homes, and generally prefer to live in houses than out in the wild. House mice are one of the most common animals in the world, and are found everywhere that humans live.