As summer gives way to fall, your garage becomes the closest thing your home has to a front door for mice. It offers warmth, shelter, and a welcome break from colder weather and increasingly scarce food in the wild.

Once inside, mice reproduce quickly, contaminating your belongings with urine, droppings, and the unpleasant odors that come with them. The best time to stop them is while they’re still in the garage, before they squeeze into the rest of your home and become a much bigger infestation.

Signs of a Mouse Infestation in Your Garage

A single mouse sighting isn’t always cause for alarm. However, repeated sightings together with the indicators below should be treated as a likely infestation.

• Mouse droppings. Look for small, dark, rod-shaped droppings with pointed ends. Fresh droppings are usually dark and somewhat shiny.
• Scratching, scurrying, or squeaking, particularly at night behind walls, ceilings, or storage areas.
• Nests and shredded materials (e.g. paper, cardboard, fabric, or insulation).
• Gnaw marks on cardboard boxes, food containers, wood, plastic, insulation, or electrical wiring.
• Rub marks along walls and tiny footprints or tail marks in dusty areas.
• A persistent musky or urine-like odor, particularly around nesting or travel routes.
• Unusual pet behavior. Your cat or dog may repeatedly sniff, paw, stare at, or scratch the same wall, cabinet, or storage area.

How to Get Rid of Mice in Your Garage Quickly

Remove Food Sources

The first step is to cut off the mouse buffet. A quick sweep of the garage should cover the following:

• Pet food, birdseed, grass seed, and livestock feed: Transfer them from their original paper or plastic bags into heavy-duty plastic or metal bins with tight-fitting lids.
• Spilled food and seed: Sweep or vacuum around shelving, workbenches, storage areas, and underneath anything you can safely move.
• Trash and recyclables: Empty trash cans regularly, and rinse food residue from recyclables. Use trash cans with secure lids.
• Forgotten food: Check workbenches, shelves, bags, and other storage areas for snacks, wrappers, or anything else that could provide an easy meal. Best practice? Avoid keeping or bringing food in the garage altogether.

Check out our guide on surprising foods mice will eat.

Clear Out Nesting Materials and Clutter

A cluttered garage gives mice plenty of resources to create hiding spots and build nests in quiet corners that often go unnoticed. Clear out or properly store materials such as:

• Old rags, towels, and clothing
• Newspapers, magazines, and loose paper
• Cardboard boxes and stacks of empty boxes
• Paper and reusable shopping bags
• Loose insulation and packing materials
• Bags of mulch, potting soil, and other garden supplies

For anything you need to keep, use lidded plastic storage totes instead of cardboard boxes and keep them off the floor where possible. This also makes signs of a mouse infestation, such as droppings and gnaw marks, easier to spot.

Set Mouse Traps Along Walls and Runways

Mice have relatively poor eyesight and rely heavily on their whiskers, or vibrissae, to sense nearby surfaces and objects. They also tend to follow familiar routes along walls rather than venture across open floor space.

This combination of physiological limitations and their nature as creatures of habit is something you can use to your advantage through strategic trap placement. Below are a few pointers to help you do it effectively:

• Place traps along walls: Position snap traps perpendicular to the wall, with the baited trigger end facing and nearly touching the baseboard. Focus on areas where you’ve seen droppings, chew marks, or other signs of mouse activity.
• Use a small amount of bait: Peanut butter is a common choice, but mice may also respond to chocolate, nuts, seeds, or small amounts of dried fruit. You only need enough mouse bait (just a dab of it will do) to encourage the mouse to interact with the trigger.
• Set several traps: House mice typically stay within 10-30 feet of their nest when food is readily available. If you keep seeing mice or fresh droppings in one part of the garage, there’s a good chance the nest or a regular feeding area is nearby. Set several traps around those runways rather than relying on a single trap.
• Keep traps out of reach of children and pets: Place them only in areas where curious hands or paws can’t get to them, or use tamper-resistant trap stations where appropriate.

A word of advice: Rodents can carry disease-causing bacteria and viruses. Wear disposable gloves when handling used traps, dead mice, or anything contaminated with rodent urine or droppings. For a more in-depth look at how to safely clean up after rodents, check out our guide.

Seal Gaps and Other Mouse Entry Points

Openings as small as 1/4 inch, about the width of a pencil or your little finger, are all a mouse needs to squeeze into your garage from the outside. That’s why sealing potential entry points should be one of your first priorities.

Your garage door is the most obvious place to start. Replace worn weather seals, especially along the bottom edge. If mice have been gnawing through softer materials (a common problem with rubber or vinyl seals), consider installing a rodent-resistant door sweep or a metal-reinforced threshold.

For holes and cracks around exterior walls and the foundation, tightly pack copper mesh or steel wool into the opening before sealing it with caulk. Do the same for gaps around garage wall penetrations, including plumbing pipes, electrical wiring, and HVAC lines.

Try Mouse-Deterring Scents (With Caution)

Strong scents such as peppermint oil are commonly used as natural mouse deterrents. Their concentrated odor can interfere with a mouse’s highly developed sense of smell, making treated areas less appealing for exploration or travel. Keep in mind that this is strictly a short-term fix—mice adapt rapidly to familiar odors and will eventually learn to ignore the scent.

To try it, add a few drops of pure peppermint oil to cotton balls and place them near suspected entry points and other areas where you’ve noticed activity. You’ll need to replace or reapply the oil every few days as the scent can fade quickly.

Other pungent-smelling home remedies, such as ammonia and cayenne pepper, are also commonly suggested, although they should be used with greater caution. Both can irritate the eyes, skin, and respiratory tract, particularly if the fumes or particles become airborne.

Clean Vehicle Interior

Your vehicle can be just as attractive to mice as the rest of your garage if crumbs and food waste are left inside. After every trip, remove takeout bags, snack wrappers, and any other food or drink containers.

Regularly vacuum and wipe under and between the seats, beneath floor mats, around cup holders, inside door pockets, and other areas where crumbs and sticky spills tend to accumulate.

Check Seldom-Used Vehicles

Have an extra car that spends more time parked than driven? Take it out regularly and give it a once-over. RVs, campers, classic cars, and other seasonal vehicles can sit undisturbed for weeks or months, giving mice a sheltered place to hide and potentially build a nest.

Check under the hood, inside the trunk, glove compartment, storage compartments, and around the spare-tire well for any signs of mice activity. Then, remove any nesting material or food using gloves.

Clean contaminated areas properly and set traps along nearby garage walls to catch mice that may still be active.

When to Call a Professional Rodent Control Service

In many cases, garage mouse problems can be managed with the combination of strategic trapping, proper exclusion, and good sanitation practices.

However, if you’ve worked through the steps in this guide and still find fresh mouse activity, it may be a sign that the infestation has become more established.

At that point, calling a professional is often the most effective way to finally eliminate the infestation and keep it from returning.

Professional rodent control goes beyond simply placing more traps or stronger bait. At Modern Pest, we follow an Integrated Pest Management (IPM) approach, an EPA-recognized strategy that combines multiple long-term control methods while minimizing unnecessary pesticide use. This includes:

• Comprehensive inspections to identify entry points and nesting sites.
• Targeted trapping and baiting based on rodent behavior.
• Exclusion work to keep mice from getting back inside.
• Habitat modifications to remove food, water, and shelter sources.
• Ongoing monitoring to detect and respond to new activity early.

Modern Pest also uses Anticimex SMART Rodent Monitoring, which collects real-time rodent activity data 24/7. Our technicians regularly analyze this information to identify movement patterns, behavioral trends, and potential infestations before they become larger problems.

That means we’re able to spot issues sooner and respond based on actual rodent activity, rather than relying solely on scheduled inspections or waiting for new signs of an infestation to appear.

Get Year-Round Protection Against Mice and Other Pests

Mice are far from the only pests that use your garage as a gateway into your home. Modern Pest’s HomeCare Green program provides year-round protection against rodents and more than 55 common household pests.

If you’re ready to put an end to recurring mouse problems and protect your home from the next pest looking to move in, call Modern Pest today at (800) 323-7378 or contact us to request your FREE quote.