How Are Mice Getting into My Home?

Posted by Mosquito Squad Plus

October 5, 2026

Your house is clean, the doors are closed, and you certainly haven’t invited any rodents inside. How on Earth did a mouse end up in your kitchen?

Mice aren’t looking for homes that are dirty, clean, or in-between. All the invitation mice require to get into your house is a small opening – like, infinitesimally small. A gap beneath an exterior door, a foundation gap or crack, or the opening where utilities enter from outside, these are just a few of the ways they make their way inside.

As we move into fall here in West St. Louis County, mice will inevitably be searching for places to shelter within during the colder months. Your home has all they need, including warmth, shelter, and possibly a steady supply of food.

How Small of an Opening Can a Mouse Fit Through?

When you look at potential entry points around your home’s exterior, like the ones mentioned above, you are probably not surprised a mouse could fit in through them. However, their reverse Houdini skills allow mice to squeeze through a hole as small as a dime.

Mice are equipped with highly flexible bodies and the ability to fit through spaces that appear far too small. If a mouse can get its head through, there’s a high probability that the rest of its body can follow.

Some of the more common places mice enter, include:

Around garage and exterior doors
Electrical, plumbing, and HVAC line entry points
Foundation cracks and gaps
Damaged exterior vents
Openings around siding and siding trim work
Unsealed spaces around basement windows and crawl spaces

Mice are also excellent climbers, so they often reach openings above the ground by climbing on rough-textured siding, overhanging branches, and other exterior features.

Where Do Mice Go Once They’re Inside Your Home?

Mice are just as interested in encountering you as you are them, which is to say not at all. They’re just as skilled at staying out of sight as they are at getting inside, preferring to nest in quiet, protected spaces. They’ll build nests and access food with little disturbance.

Some of the more common hiding places are inside attics, basements, crawl spaces, in wall voids, and behind kitchen appliances. You might also find evidence of mice inside storage areas, especially ones with cardboard boxes, paper, or fabric they can use for nesting.

Will Mice Leave Your Home After Winter?

Sure, in a perfect world, if mice are living unnoticed indoors for the winter, they’d pack their bags and head outside for spring and summer. But that’s not really how they operate. Once shelter, nesting, and food sources are found to be reliable in your home, mice have little reason to venture back out – at least voluntarily.

At Mosquito Squad Plus of West St. Louis County, we know that truly effective rodent control involves more than waiting for the season to change to catch them on the way out. It also requires a wholly unique approach to other types of outdoor pest control. Our rodent control services address mouse and rat activity in and around your home to help you manage existing problems and reduce the likelihood of future issues.

Whether you’ve spotted a mouse in the kitchen, discovered droppings in your basement, or heard that unnerving scratching inside your walls at night, we’re here to help with year-round rodent control solutions.

Where Do We Offer Pest Control Services?

Mosquito Squad Plus of West St. Louis County provides our full suite of outdoor pest control, including rodent control services throughout the West St. Louis County and St. Charles County areas, including these cities and beyond:

Search for West St. Louis rodent control and Call Mosquito Squad Plus.

Mosquito Squad Plus of West St. Louis County will help you fight outdoor pests, including deer, rodents, cockroaches, and more that invade our private spaces. We also treat mosquitoes, ticks, stink bugs, spiders, gnats, and more!

Mosquito Squad Plus of West St. Louis County additionally offers a 100% satisfaction guarantee. If you are not satisfied with your pest control treatment, call us within 21 days for a complimentary repeat treatment.

Call Mosquito Squad of West St. Louis County today for rodent control near me. Get in touch with us by filling out our form online or calling us at (636) 597-8684 for a free quote.