How Do Mice Get Into Your House in the Fall?

Short answer: When the weather cools in the fall, mice look for a warm place with food, and your house fits the bill. They squeeze through gaps as small as a dime, usually low on the house where utilities enter, around the garage, and up under the eaves.

Every fall the calls pick up. People hear scratching in the wall or find droppings in a drawer right around the first cold snap. It is not random. Mice are reacting to the same thing you are, which is the temperature dropping.

Why fall is mouse season

Through the warm months mice are happy living outside in fields, wood lines, and landscaping. Once nights get cold and outdoor food gets scarce, a heated house with a stocked pantry becomes the best real estate around. So they move toward the warmth, and that means toward us.

The dime-sized gap

A mouse can fit through a gap about the width of a dime, roughly a quarter inch. Their skulls are the limiting factor, and if the head fits, the rest follows. That is why sealing a house is harder than it sounds. The openings that let them in are small and easy to miss.

Where they actually get in

• Gaps where pipes, cables, and gas lines pass through the wall
• Under and around garage doors with worn weather seals
• Foundation cracks and gaps in crawlspace vents
• Up under the eaves and roofline where gable vents and soffits meet
• Around dryer vents and AC line sets

How to keep them out

The lasting fix is exclusion, which is a fancy word for sealing them out:

• Seal gaps with steel wool packed into caulk, since mice chew through foam and caulk alone
• Replace worn garage and door weather stripping
• Keep firewood, mulch, and shrubs back away from the foundation
• Store pantry items and pet food in sealed containers

Traps handle the mice already inside, but if you do not close the entry points, more just follow. For how to tell whether you have a problem yet, read the signs of a rodent problem.

The Alabama angle

Our fall comes in fits and starts, with warm weeks broken up by sudden cold snaps. Each cold snap pushes another wave of mice to look for shelter, so the season can stretch out longer here than people expect. Homes near wood lines and creeks, common around Birmingham, tend to see them first.

Hearing scratching in the walls?

Our rodent control finds the entry points and seals them, not just sets a trap. Call or text (205) 855-7975 for a free assessment.

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How small a gap can a mouse fit through?

About the width of a dime, roughly a quarter inch. If a mouse can fit its head through, the rest of its body follows.

Why do I suddenly have mice when it gets cold?

Cooler weather and scarce outdoor food push mice to seek warmth and shelter, and a heated home with food is the ideal spot. Fall is their prime moving season.

Do traps alone get rid of mice?

Traps remove the mice already inside, but unless you seal the entry points, more will keep coming in. Sealing the house is what ends it.