Mice are using this hole to get into your home. Try using a small, handheld mirror and take a good look under the siding and around porches for hidden openings. Shining a flashlight on the mirror will help in your search.
Mouse holes are normally found along the lower edge of the home or around air conditioner condenser lines or other piping going into the house. On wood siding or stucco homes mice are capable of climbing and the entry holes can be under eaves, around windows, chimneys, or any other holes in the siding.
Don’t encourage mice to live in your garage. Keep birdseed, grass seed, dog food, dry flowers, or any other food source in sealed containers. Keep a mousetrap set to catch any mice that wander into the garage.
After a fresh snow take a walk around your house. Look for mouse tracks in the snow. They appear as tiny sets of tracks and they may lead you to a mousehole in your home.
Every home has cracks and holes. Mouse holes will normally be thumb sized and may have chewed edges or urine stains around them.
Look for holes that don’t have cobwebs in them. This indicates current usage.
Reset and reuse mouse traps after catching a mouse. That trap now smells like Uncle Bob and other mouse family members will investigate the trap and get caught.
Be careful vacuuming mouse droppings. Use a vacuum with a HEPA filter to minimize a health risk for you and your family.
Don’t leave pet food in dishes on the floor at night. Mice will find this food source and stash it around your home. You need to try and minimize the available mouse food around your home until you eliminate the mouse problem.
Noises in the attic can mean mice are living there but it could also be birds, hibernating bats, or squirrels. Taking a quick peek into the attic can show you rodent droppings or tunnels in the insulation that are clues to the rodent identity.