Rat and mouse articles · Updated
Rats and mice in your car engine: what to do
Rodents nest in parked cars because engine bays are warm and sheltered, often next to a garage full of seed and pet food. Check the air filter box and cabin filter for nests, look for chewed wires, and fix the garage: seal the door and remove food.
A warning light comes on after the car sat for a week. You pop the hood and find shredded insulation in the air filter box, or droppings on the engine cover. Mice and rats use parked cars as shelter, especially in a Plano garage that opens onto an alley and stores bird seed and dog food a few feet away.
The fix is mostly about the garage, not the car. Here's what to check and what to change.
Why rodents like cars
An engine bay is warm after a trip, sheltered from weather and full of soft material for nests. The air filter box and the cabin air filter housing are favorite spots. A car that sits for days, like a second car, a weekend car or one parked while you travel, gives rodents time to settle in.
What to check under the hood
Before you start a car you suspect has visitors, open the hood and look. Wear gloves.
- Nest material in the air filter box: shredded paper, insulation, leaves
- Droppings on the engine cover, battery or fender wells
- Chewed wiring, hoses or insulation
- Food stashes: seeds, pet food, pecans
- A musty or urine smell from the vents when you run the fan
Something in the attic or the garage?
Want a local rodent technician to look at it? Same-day appointments are often available. (972) 325-9652
If you find damage
Don't take a car with chewed wires on the road if a warning light is on. Have a mechanic check it. Tell them it's rodent damage so they look at the whole harness. Then call your insurance agent and ask whether your policy covers it. Coverage varies a lot.
Clean nests and droppings the way the CDC recommends for any rodent mess: gloves, spray until very wet with disinfectant or a bleach solution, let it soak about five minutes, wipe up with paper towels. Replace the cabin air filter if nesting reached it.
Fix the garage
Most car problems in Plano start in the garage. Rubber door seals harden and crack in the summer heat, and a slab that has settled at one corner leaves a gap the seal can't close. The alley side of the garage is where trash carts and fences give rats a highway.
- Replace a worn overhead door bottom seal and side stops
- Store seed, pet food and grass seed in metal cans with tight lids
- Get boxes and bags off the floor
- Keep the garage door closed at night
- Set snap traps along the walls, out of reach of pets
Cars parked outside
Driveway and alley parking has its own risks. Rats in shrubs and under decks can reach a car parked next to them. Park away from dense shrubs, ivy and woodpiles if you can. Don't leave food wrappers or pet food in the car. Take cars that sit out for a spin regularly so nests don't have time to build.
Signs while you're on the road
Sometimes the first clue shows up while you're behind the wheel. A musty or urine smell when you turn on the fan, weak airflow from the vents, a warning light that wasn't there before or a burning smell are all worth a look under the hood. A clogged cabin air filter full of nesting material can choke the airflow. Pull over somewhere safe and check before it gets worse.
Alley garage habits
Most Plano garages open onto the alley, where trash carts and fences give rats a travel route at night. Close the overhead door as soon as you pull in, especially after dark. Don't leave the door cracked open for a cat or for airflow in summer. Keep the area right outside the door clear of bags, boxes and stacked lumber, and keep the trash cart lid closed.
Boats, RVs and stored vehicles
Anything that sits for months is at risk: boats, campers, classic cars, lawn tractors. Check them every couple of weeks, keep food out and set traps around them. Pull boat cushions and RV mattresses out for storage in sealed bins if you can. Cover air intakes and exhaust openings with mesh while stored, and remove it before you start the engine. Lakeside households in The Colony and Wylie deal with this a lot.
After you clean out a nest
Once the nest is out, look for where the rodents came from. A nest in the car almost always means they're living in the garage or close to it. Set a few snap traps along the garage walls for a week and check them daily. If you catch something, the garage has a gap to close.
When to call
If you keep finding nests or droppings, rodents are living in the garage. A technician can find the gap and set up trapping. Garage, shed and car rodent control covers what that job includes.
Something in the attic or the garage?
Ready to have the gaps found and closed? Call and describe what you're hearing or finding. (972) 325-9652
Common questions
Will mothballs or dryer sheets keep mice out of my car?
They're not a reliable fix, and mothballs give off fumes you don't want in a closed garage or car. Seal the garage and remove food instead.
Does insurance cover rodent damage to a car?
It depends on your policy. Call your agent and ask before repairs start.
Is it rats or mice in my engine?
Check the droppings. Mouse droppings are a quarter inch or less; rat droppings are about half an inch or more.
Should I leave the hood up?
Some people do overnight to make the engine bay less sheltered. It may help a little, but sealing the garage matters far more.
Do rodents really eat car wiring?
They gnaw on wiring and hoses under the hood. Have a mechanic check any chewed wires before you rely on the car.