We frequently see mice scampering out of sight in our garage when we turn the light on. We might see them and their droppings for a few days but then they disappear, until a couple months later when we see mice again. Are these the same mice and how do we keep them out?

M. M., Uxbridge, MA

Hard to say whether you’re seeing the same mice each time, or whether they are new invaders, or even the offspring of earlier visitors. When the mice disappear for a while, they could be leaving the garage after a brief exploration, but it’s more likely the mice have moved into other areas of your house.

Mice that have found their way into a garage usually can follow pipe runs or wires or even ceiling beams into attic spaces, wall voids, or the main body of the house. Garage mice will utilize vents, furnace ducts, or the attic access opening to get further inside (see Got Mice in Your House?).

HOW ARE MICE GETTING INTO THE GARAGE?

This first question doesn’t take a lot of thought. Mice can simply walk into a garage if the door is left open. More often though, they will find their way in at night through openings around the garage door. It’s rare to find a garage door that seals tightly enough at all points to keep mice out.

If you stand in your dark garage and look out towards a sunny day, you will see all of the light “leaks” along the edges of the garage door, in the corners where the rubber threshold at the bottom meets the side walls, and maybe even under the worn bottom rubber gasket (see Maintain Your Garage Door to Keep Mice Out). Every light gap is a space where a mouse could enter.

HOW TO KEEP MICE OUT OF YOUR GARAGE

There are two primary steps to keep mice from getting into your garage…and then into your house. First, remove any food or other items that attract mice to your garage (both inside and out), and then seal up any openings that mice can use to get inside:

1. Replace gaskets and rubber thresholds and otherwise rodent-proof the garage door.

2. Store pet food, birdseed, and grass seed in heavy containers with tight lids.

3. Don’t leave pet food in bowls in the garage overnight, and if you have a cat’s litter box in the garage, clean it regularly.

4. Store garbage and recycling in containers with tight lids and dispose of them ASAP.

5. As much as possible, keep boxes and items up on shelves and off of the garage floor. Don’t hoard cardboard boxes, stacked newspapers, and old rags that provide hiding places and nest material for mice.

6. On the outside: avoid stacking wood, brush, or other attractions for mice near the garage. Move garbage cans, recycling bins, and pet bowls away from the garage door.

For more information on garage mice:

• Why Your Garage Makes a Nice Home for Mice!
• How to Keep Pests Out of Your Garage

For more help with garage mice, or mice anywhere in your home, call Colonial Pest Control. We can also help you mouse-proof your garage by sealing openings that mice use to get inside and move around.

For information on what Colonial Pest is doing to help keep your family safe while solving your pest problems, see our COVID-19 page.