Flies in your garage are more than a nuisance—they can contaminate surfaces, spread bacteria, and make the space unpleasant to use. This guide gives you a practical, proven system to keep flies out, from sealing entry points to removing what attracts them. You’ll need basic tools and materials, most of which you may already have.
What You’ll Need
- Caulk and a caulking gun
- Weatherstripping (foam tape or rubber)
- Door sweep (also called a door bottom seal)
- Fine mesh screen or fly screen patch kit
- Screwdriver and screws
- Scissors or utility knife
- Cleaning supplies (broom, mop, trash bags)
- Fly traps (sticky tape, jar traps, or UV light trap)
- Insecticide spray (optional, for indoor use)
Step-by-Step
- Identify all entry points. Walk around your garage during daylight and look for gaps around doors, windows, vents, and where pipes or wires enter. Also check the bottom edge of the garage door—it often has a gap. Use a flashlight to spot small cracks.
- Seal gaps and cracks. Use caulk to fill any cracks in walls, around windows, and along the foundation. For larger gaps (like around pipes), use expanding foam or stuff with steel wool before caulking. Make sure the caulk is paintable if you want to match the surface.
- Install weatherstripping. Apply foam tape or rubber weatherstripping around the sides and top of the garage door, and around any entry doors. Clean the surface first so the adhesive sticks. Press firmly and let it set for a few hours.
- Add a door sweep. Attach a door sweep to the bottom of the garage door (if it doesn’t have one) or to any pedestrian door. Measure the width, cut the sweep to size, and screw it into place. The rubber flap should touch the floor lightly.
- Repair or add screens. If you have windows or vents, ensure they have tight-fitting screens. Patch any tears with a screen repair kit. For vents, consider adding fine mesh over the exterior openings.
- Eliminate attractants. Flies are drawn to food, garbage, pet waste, and moisture. Remove any trash, recycling, or compost from the garage. Clean up spills, especially sugary drinks or pet food. If you store pet food, keep it in sealed containers.
- Manage moisture. Fix any leaks or standing water. Use a dehumidifier if the garage is damp. Keep the area dry, as flies need moisture to breed.
- Set up traps. Place fly traps strategically: near doors, windows, or where you see the most flies. Sticky tape works well for small numbers. For larger infestations, use a jar trap with bait (like vinegar and dish soap) or a UV light trap placed away from entrances.
- Use insecticide as a last resort. If flies persist, apply an indoor-safe fly spray according to label directions. Spray along door frames and windowsills, but avoid spraying food surfaces or pet areas. Always follow safety instructions.
- Maintain a clean garage. Sweep regularly, take out trash promptly, and keep doors closed when not in use. A clean garage is less inviting to flies.
Common Mistakes
- Ignoring the garage door gap. The biggest entry point is often the bottom of the garage door. A worn or missing seal lets flies in easily.
- Using only traps. Traps catch flies but don’t stop new ones from coming in. Sealing entry points is the primary defense.
- Forgetting about vents and exhaust fans. These are common entry routes. Make sure they have screens.
- Leaving pet food or water out. Even a small bowl can attract flies.
- Not cleaning up immediately. A single spilled drink or forgotten trash bag can keep flies coming back.
Tips
- Check the weatherstripping and door sweep every few months; they wear out.
- Use a flashlight at night to spot gaps—light shining through means flies can get in.
- Place fly traps away from seating areas or workbenches, as they can be smelly.
- Consider planting fly-repellent herbs like basil or mint near the garage entrance (they may help, though not guaranteed).
- Keep a fly swatter handy for the occasional straggler.
- If you have a window, keep it closed or screened.
Troubleshooting
Flies still getting in after sealing? Check for gaps you missed, especially around utility lines, conduits, or where the wall meets the floor. Use a caulk or foam to fill them.
Traps aren’t catching many flies? Try a different bait. Flies are attracted to different scents depending on species. Vinegar works for fruit flies, but house flies may prefer rotting meat or commercial bait. Move the trap to a different location.
Garage smells after using traps? Empty and clean traps regularly. Consider using a UV light trap instead of bait traps, which are less smelly.
Flies seem to be breeding inside? Look for damp organic material like a wet mop, spilled grain, or a dead rodent. Remove the source and clean thoroughly.
Weatherstripping doesn’t stick? Clean the surface with rubbing alcohol and let it dry completely before applying. Use a stronger adhesive if needed.
Frequently Asked Questions
Q: Why are there so many flies in my garage even though it’s clean?
A: Flies can enter through tiny gaps you might not see. Also, they may be breeding in nearby areas like compost piles or trash cans outside.
Q: What’s the best fly trap for a garage?
A: It depends on the size of the problem. For a few flies, sticky tape is enough. For a larger infestation, a UV light trap or a jar trap with bait works better.
Q: Can I use a bug zapper in the garage?
A: Yes, but they can be loud and may attract more flies from outside. They’re more effective for mosquitoes and moths.
Q: How often should I replace weatherstripping?
A: Check it every few months. If it’s cracked, brittle, or no longer seals tightly, replace it—usually every couple of years.
Q: Will keeping the garage door closed all the time help?
A: Yes, but it’s not always practical. Sealing gaps and using screens is more effective because flies can still enter through small openings.
Q: Are there any natural repellents that work?
A: Some people find that essential oils like eucalyptus or citronella help, but they’re not reliable. The best approach is prevention and traps.