How to Protect Your Car From Rodents
CR offers clever solutions to critters nibbling at your wires
Rats! You can buy the most reliable car on Earth and still find convoluted electrical gremlins, fluid leaks, and even outright failure when rodents take up residence and begin chewing on wiring, hoses, plastic, and other critical car parts.
This is especially a risk for cars stored over the winter, and those that have been parked for extended periods during the pandemic.
Rodent-inflicted damage is an age-old problem that some observers say is increasing as automakers use more plant-based biodegradable materials to reduce waste. Several class-action lawsuits have been filed against major automakers in recent years alleging that soy-based products were to blame, but these court cases were later dismissed.
Pest control company Terminix considers the temptations of tasty materials to be a myth, and instead, it blames rodent biology and their need to constantly chew, thereby preventing their teeth from growing too long. It turns out that feasting on cars is more prevalent than you might think.
We uncovered various technical service bulletins from Ford, General Motors, Honda, Toyota, and Subaru instructing their technicians how to remedy chewed wiring harnesses.
Some Consumer Reports staffers also have stories of small, furry creatures chewing through power steering lines, filling engine intakes with acorns, and plugging up air-conditioning ducts with their nests.
How to Avoid Attracting Critters
- Ideally, park away from places that are known to draw rodents, such as near trash bins or natural food sources, such as vegetable gardens.
- Park in a sealed garage, if possible, and keep the doors closed.
- Make sure the garage doesn’t have stored food and prime nest materials like newspapers, cardboard, straw, rags, and patio furniture cushions.
- Look for gaps around garage windows and doors for possible places that rodents can sneak in. Weather strips under side doors can help seal them. Likewise, inspect the vertical seals on retractable garage doors for damage.
- Don’t store trash cans used for food waste in the garage.
- Keep the car interior free from food wrappers; their scent can draw rodents.
- Move the car regularly, discouraging varmints from taking up residence. And occasionally honk the horn before starting the car to scare away any napping critters.
How to Get Rid of Furry Vandals
There are specially made spray products that promise to deter rodents that you could mist under the hood and around the vehicle, if garaged. Peppermint oil and cayenne pepper are reported to deter rodents. Note that spray products will need to be reapplied routinely, because they can wear away and rinse off.
There are ultrasonic devices that emit sounds to deter rodents, but at a frequency that humans can’t hear. However, their effectiveness is in doubt.
For storage, placing mothballs under the hood can help. (Don’t use them inside the car, or you’ll be stuck with that awful smell.)
There is a clever solution in a TSB from Honda: rodent-deterrent tape, essentially an electrical tape treated with super-spicy capsaicin, which Honda describes as “the stuff that puts the fire in a bowl of five-alarm chili.” The tape (part number 4019-2317) comes in a 20-meter roll, about 22 yards, and it is available through dealers and available online ($43).
We bought a roll of Honda’s rodent-deterrent tape to check it out. Beyond the cute rat graphics and gray color, it deceptively seems like regular electrical tape to us humans. There is no tear-inducing odor, but it does carry a label that warns against prolonged exposure to skin. Despite dares and double dares, we did not taste it and will trust that it is potent enough to deter even the most ravenous varmint.
Other suggestions for dealing with rodents under your hood include installing a metal mesh around wiring harnesses and rubber hoses and across any openings where rodents could crawl into your ventilation or intake systems.
Placing rodent traps around the garage can reduce the population, but just be careful of exposing domestic animals and children to poisons or dangerous snap traps.
If the rodents are winning the war despite following these tips, reach out to a local pest control service. They are trained in how to best combat stubborn rodent issues and can address your specific challenges.