How To Keep Pesky Mice From Under the Hood of Your Car

Reviewed by

Richard McCuistian, ASE Certified Master Automobile Technician

Technical Reviewer at CarParts.com

Written by CarParts.com Research Team - Updated on February 2nd, 2024

Reading Time: 6 minutes
Summary
  • Mice like to hide and keep warm under the hood of your vehicle during the winter.
  • To keep them away, you can try making noise or turning up the heat. Park in a sunny or hot spot in the summer to keep them out.
  • Some indications that your vehicle has mice are vehicle damage and signs of habitation, such as sight and scent of rodents.

Have you ever been surprised to find mice or rats scurrying away from your chassis as you start your car? It can be an alarming experience and one you don’t want to happen again. It’s chilling to think what would happen if they stayed under the hood of your vehicle. They can also wreak havoc on your vehicle’s electric lines and insulation.

Cats and squirrels are also an issue, and dogs can chew the wires underneath on pickups, vans, and SUVs but we’ll mostly talk about mice in this article.

Let’s look at why the little mammals insist on staying in such a dangerous area and what to do to keep them away.

Why and How Do Mice Get in Cars?

The first step to keeping mice out of your vehicle is learning how they get in. During the winter, mice like to shelter under the hood of your vehicle for warmth and protection from the elements. Mice are more likely to nest in your car during the colder months, but they can also stay in your vehicle during warmer months to avoid rain. Vehicles in general, especially those that are left parked for long periods of time, make for a convenient home for them.

The lady who owned this Explorer lived next to a cotton field and rats kept carrying cotton from the field under her hood and building a nest. | Image Source: Richard McCuistian
They also damaged the injector wires and she put poison under the hood in an attempt to get rid of them but they just kept coming. | Image Source; Richard McCuistian

Once you close the doors and make sure the hood is latched properly, it’s tempting to think your vehicle is safe from rodents, but unfortunately this isn’t the case. Mice come in many sizes, and while some are too large to fit between the parts of your chassis, others are small enough to squeeze through openings as tiny as a dime.

Mice usually enter under your engine and move through the rest of your vehicle from there. They can also enter from holes around the cables, vents, steering columns, and pedal shafts. Leaving your windows cracked open gives them a way in as well.

Keeping Mice Away from Your Vehicle

To keep mice away from your car, it’s best to keep things as uncomfortable for them as possible. Rodents hide in toasty, safe areas like your car’s airbox and under the plastic engine cover. They’ll also settle in your cabin if given the chance. You’ll want to both prevent them from getting to these areas and dissuade them from staying.

This wire harness damage was done by squirrels on a 2007 F150, which became a no-start until the damage was repaired. | Image Source: Richard McCuistian

Prevention

To keep mice away from your car, keep your vehicle in a garage and always make sure the windows and sunroof are closed. Because mice prefer areas with vegetation, parking your car in tall grass or in a wooded area raises the possibility of their entry. In addition, any small openings in the window and sunroof are sure to invite trouble.

Keeping your vehicle’s cabin clutter-free is also important. Any leftover food or potential nesting materials will entice nearby rodents to set up shop.

Dissuasion

To dissuade rodents from staying in your vehicle and under your hood, try using rodent-repellent scents like peppermint oil and essential oils that are made from cloves and cayenne pepper. Soaking cotton balls in these scents and leaving them in your vehicle will help keep the rats away if you refresh them weekly. Red cedar also gives off an anti-rodent scent and comes in the form of shavings, sawdust, and mulch. Pest control sprays and odors can also work, but might be a little strong for the small space.

This anti-rodent tape works, but you can also mix some hot sauce and vegetable oil and spray it on your hoses and harnesses under the hood to discourage critters from chewing on things. | Image Source: Richard McCuistian

Besides scents, you can tape up the wires under your hood with rodent-deterrent tape to protect them from damage. The tape has capsaicin, the chemical found in hot peppers. You can try using ultrasonic sound repellents and rodent traps as well.

Signs of Mice in Your Car

You might be wondering if your preventive measures are even necessary. Maybe mice don’t like your car at all. Look out for these signs to be sure:

Vehicle Damage

Whether it’s chewed wires under the hood or damaged upholstery, rodents are without a doubt destructive creatures. You might find that some of your vehicle’s mechanical parts are failing due to their tampering.

Signs of Habitation

The scent and sight of rodent droppings around your vehicle will also be a clear indicator that you need to address the problem as soon as possible. These come in the form of tiny, rice-like pellets scattered around the vehicle. Strange scents from your vents are also a possible giveaway for your furry, unwelcome guests. You might even find their nesting materials in the air filter box or other out-of-the-way areas of your vehicle.

Getting Rid of Car Mice

If you suspect your vehicle already has mice in it, you’ll need to get rid of them before some of the above preventive measures will work. Make the vehicle an uncomfortable area for them by playing loud music, making noise, and turning up the heat. You can even try honking the horn to affect their sensitive hearing. In the summer, park in a sunny or hot spot to sweat them out.

As we’ve mentioned, you can also lay out traps and use specific scents to dissuade them from staying.

Cleaning Your Infested Car

Now that you know how to keep mice out of cars in winter and summer, you might have some cleanup to do. After getting rid of the mice in your car, it’s time to inspect, detect and disinfect according to the Center for Disease Control (CDC). Make sure to wear proper protective gear like rubber gloves and long sleeves because mice can carry a host of nasty diseases.

Step 1

Check under the hood, in the vehicle doors, and the trunk. Air out the interior and the engine compartment for 20 minutes to reduce any noxious odors. Once that’s done, check the vehicle interior and remove any battery cables to inspect the engine compartment. Find and dispose of any nesting materials and rodent corpses. Leave the waste until you’ve properly disinfected the materials.

Step 2

Avoid using a vacuum cleaner or high-pressure sprayer on rodent waste and contaminated surfaces until you’ve disinfected them properly. Soak any affected materials with disinfectant by spraying them and letting them sit for the time allotted by the label instructions. Use a paper towel to pick up materials and dispose of them in the garbage. Get rid of any nesting materials in the air intake system and replace the necessary filters.

Step 3

Clean everything with another round of disinfectant once the droppings and nesting materials are gone. Wait for everything to dry before reconnecting the battery. Wash your gloved hands with soap and water or disinfectant and then wash your hands with warm water and soap.

Learning how to get rid of mice in your car and keep them away is important. You certainly don’t want to catch anything from their droppings or pay thousands to repair the damage they cause. Prevention is the best answer to rodents in your vehicle, but you should also know how to evict them and clean up after them.

About The Authors
Reviewed By Richard McCuistian, ASE Certified Master Automobile Technician

Technical Reviewer at CarParts.com

Richard McCuistian has worked for nearly 50 years in the automotive field as a professional technician, an instructor, and a freelance automotive writer for Motor Age, ACtion magazine, Power Stroke Registry, and others. Richard is ASE certified for more than 30 years in 10 categories, including L1 Advanced Engine Performance and Light Vehicle Diesel.

Written By CarParts.com Research Team

Automotive and Tech Writers

The CarParts.com Research Team is composed of experienced automotive and tech writers working with (ASE)-certified automobile technicians and automotive journalists to bring up-to-date, helpful information to car owners in the US. Guided by CarParts.com's thorough editorial process, our team strives to produce guides and resources DIYers and casual car owners can trust.

Any information provided on this Website is for informational purposes only and is not intended to replace consultation with a professional mechanic. The accuracy and timeliness of the information may change from the time of publication.

Share
Published by
CarParts.com Research Team and Richard McCuistian, ASE Certified Master Automobile Technician