How do I get mice out of my car and keep them out?

Mice move into cars because a parked car is dry, sheltered and often has crumbs in it. You can get them out without snap traps or poison: take away the food, clear the nest safely, catch the mice alive, then have a garage check for damage. Keeping them out after that is mostly about where you park and what you leave inside.

It happens to careful owners, on camping trips, in city garages and in new cars. It is not a sign you did anything wrong.

Clear it out safely

1. Take out all food. Snacks, wrappers, pet treats, bags of shopping, anything with a smell.
2. Open the doors and let it air before you start cleaning.
3. Wear gloves. Spray droppings and nest material with disinfectant and let it soak, then lift it out with paper towels and bag it. Health agencies such as the US CDC advise wetting rodent droppings first rather than sweeping or vacuuming them dry, because that lifts dust you can breathe in.
4. Leave hidden nests to a garage. If the nest is behind a panel, in a wheel arch or in the heater box, ask a garage or a car valeter to take it out. Door and pillar trims can hide airbag parts and wiring, so do not pull them apart yourself.

Get the mice out alive

Snap traps are not your only option. Set two or three live catch traps inside the car overnight, on the floor and in the boot, with a small dab of peanut butter. Close the doors so nothing else can reach them. Check every morning, and release as local law allows: your council or wildlife body can tell you where. Keep going until the traps stay empty for several nights and no new droppings appear.

Dogs and kids: traps go inside the closed car, where a dog or child cannot open them. Keep the dog out of the car until it has been cleaned, and keep it away from nest material and droppings. Children should not handle trapped mice.

Check for damage

Mice chew. Ask a garage to look at wiring, hoses and insulation in the engine bay, and to check the cabin air filter and the engine air filter for nest material. A dashboard warning light that appeared after the mice did is worth mentioning. If there is damage, ask your insurer whether rodent damage is covered, as policies differ.

Get rid of the smell

• Replace the cabin air filter, as nest material and urine in it can keep the smell going.
• Wash removable mats and seat covers, and wipe hard surfaces with disinfectant.
• If the smell lingers, a valeter can deep clean the upholstery and carpets.

Keep them out

• No food left in the car, not even sealed snacks.
• Park away from bins, hedges, log piles, bird feeders and long grass where you can.
• Use the car regularly. A car that sits for weeks is a quieter home.
• Find the source. If mice moved from one car to another, they are probably living nearby, in a garage, shed or hedge. Check there, and seal a garage the way you would a house: see sealing gaps.

What people try that does not do the job

Cotton balls with peppermint oil are the most common tip. Reports are anecdotal at best, and a mouse with a warm nest and food will not leave because of a smell. Ultrasonic gadgets for cars fall into the same group. Glue traps are cruel and catch whatever touches them, so leave those out too: more in are glue or bucket traps humane.

If mice keep coming back, damage keeps appearing or the nest is somewhere nobody can reach without taking the car apart, that is a job for a garage and, for the parking area, a pest controller who does proofing. The mice and rats guide covers the signs to watch for.