Packrat Nests in Car Engines: What to Do in Apache Junction.

• Do not start the engine if you can see nest material or smell something burning.
• Take photos of the nest and of any chewed wires or hoses.
• Keep children and pets away from the vehicle.
• Wear gloves and do not touch droppings or nesting material with bare hands.
• Call a professional who can handle both the animal and the parking spot.

A vehicle that has been sitting is the most likely home. A car that is driven daily is disturbed too often for most animals to settle in, though they may still visit at night.

To a small animal, an engine bay offers shelter, warmth after a drive and a lot of nooks. The space beside the engine, the air filter box and the area near the battery are all dark and enclosed. Cabin air intakes near the windshield can be reached from outside too.

Packrats are known for collecting material and building a large nest, called a midden, from sticks, cactus pieces and whatever else they find. Mice and rats are also possible, and they build with finer, shredded materials like paper, insulation and fabric.

Rodents gnaw constantly. In a vehicle that can mean wire insulation, hoses, sound-proofing and even plastic fittings. Damage may show up as a warning light, a rough start or an odd smell, or it may show up only when a mechanic looks.

Exposed wire is a safety concern. It can short and, near flammable debris, cause a fire. A mechanic or auto electrician should repair vehicle wiring, and a rodent service should deal with the animal.

Nests and droppings can carry germs. The CDC advises against sweeping or vacuuming them dry. Instead, air out the space, wear gloves, wet the material with disinfectant, wipe it up with paper towels and bag the waste. The steps are in the safety box on this page and the linked CDC guidance.

If you do not want to handle it, ask a professional. For the vehicle itself, vehicle and car rodent removal explains how we handle nests and the parking area.

Removing the nest is only half the job. If the vehicle goes back to the same spot, the animal can come back too. Look at where you park.

• Is there food nearby, such as pet food, birdseed or spilled seed?
• Are there plants, brush or stacked material that give shelter against the parking spot?
• Does the garage have gaps at the door corners or along the walls?
• Does the vehicle sit unused for days or weeks?

A technician can check the spot and close the gaps. See garage and basement rodent control for the garage side of this.

If you can, park in a closed, sealed garage. Remove food and clutter from the garage. Open the hood once a week and look. A small amount of disturbance is often enough to make a vehicle less attractive.

If the vehicle will sit for a long time, check it before you start it. Our guide on leaving a house or vehicle empty has a short list for that.

Call if you find a nest, see chewed wiring, smell something burning or musty from the vents, or hear scratching. Call early. A nest that is found on day one is easier to deal with than one that has had weeks to grow.