Whether it's a present our cat brings us, a glimpse of one scurrying around the house, or finding them in a trap, rodents are among us. Rats, mice and other rodents want a safe environment to nest, raise their young and stay away from predators. Some of these safe havens can be found in the nooks and crannies of our vehicles.

However, that's bad news because rodent damage is usually excluded from auto policies. Therefore, the importance of protecting vehicles from rodent damage only continues to grow as the cost to repair cars has increased.

Several factors contribute to the increased cost of rodent damage, including the rise of safety technology that comes with a hefty repair price tag. The growing complexity of vehicles, particularly with the increased adoption of electric vehicles (EVs), is resulting in more parts and labor hours per repair, according to CCC Intelligent Solutions's “Crash Course Q3 2024 Report." Additionally, the amount of electric vehicles (EVs) on the road has risen—and the average repair cost for an EV is 46.9% higher than that of a non-EV, the report says.

Rodent damage risks rise when cars are not used frequently, a factor of particular concern among insureds who have more than one car or who collect classic cars.

I personally collect cars and my own experience with rodent damage has been revealing. I live in a subdivision nowhere near a farm. At one time, I had 10 cars and six of them exhibited either damage or infestation. I've found rodents in places from the blower motor for the car interior fan to the air filter box under the hood. I've encountered nests in door panels and on top of engines. The grossest of all is finding fecal remnants on the dashboard. With one of my trucks, rodents not only filled it with acorns and nesting material, they stripped all the insulation out of the truck hood to nest.

The consequences of these infestations ranged from various cleanings and wiring repairs to really expensive dealership visits. We're talking $1,800 to $25,000. The cars that were affected were less than seven years old, so they had a fair amount of contemporary electronic features. My BMW i8 was attacked twice in two weeks. Both times, the dealership found nests in the electric drive compartment.

Dealerships and oil change or tune-up shops service three to four instances of rodent damage a month, with an average cost of $2,000 to fix the immediate source of the problem, according to a CoverSeal survey. There are 18,000 dealerships in the U.S., according to Automotive News. At four instances a month costing a customer $2,000 an incident, that's nearly a total of $145 million in damages per year. Add the oil change and tune-up shops and you're closer to $200 million. 

What should you do about these pests? Education is one of the first lines of defense in preventing costly rodent damage. By sharing quality information with your clients, you can avoid uncomfortable calls where they are upset after discovering their policy excludes rodent damage.

Here's what I've tried, what worked and what didn't:

1) Rodent traps. These do help reduce the available infestation population. While the hope is the traps get them before they get into our car, putting traps close to cars can actually attract rodents into the cars. Rodents are cannibals, so a dead mouse is just more food for its brethren. Today, smart traps can connect to your phone and send you a notification when a critter is caught, reducing your maintenance time and making sure you respond to the trap when its activated. 

2) Poison bait. While this can be effective, there are downsides to this method. Animals that we want to keep—like hawks, owls and our pet cats—can ingest the poisoned dying rodents and get poisoned too. Another unfortunate outcome I experienced was that rodents gathered up the poison pellets and brought them back into my truck blower box—so, when I turned on the heater, it ground the pellets up and blew them back in my own face. 

3) Feline spray. This emulates the smell of cat urine. It's nasty. While it probably works, it also makes your car smell really bad and also has to be reapplied periodically.

4) Irish spring flakes, moth balls, peppermint oil or dryer sheets. The internet suggests a range of less invasive solutions to drive out vermin with strong smells. I tried them all and none helped. That shouldn't be a surprise. Rodents thrive in sewers, garbage dumps and some of the worst-smelling places on earth. They get used to smells. Also, a solution must cover the sensitive wiring harness that runs the length of the car, not just the engine compartment.

5) Noise makers and strobe lights. A study conducted in 2002 for the Journal of Agricultural and Urban Entomology found that noise makers and strobe lights decreased the amount of rodent presence for two to three weeks before the rodents became used to the environment. The bottom line is that they are not an effective long-term solution. 

Some other mitigation suggestions have good intent but are not always practical: 

1) Don't store food in your car. Sure, that's a common-sense suggestion. However, my infested cars had no food in them.

2) Move your car routinely. If I had one car, that's probably something I would do naturally. This is somewhat helpful. However, I did have a car infested after sitting just one day. 

3) Lift your engine hood. This exposes the rodents to predators and it will reduce their entry into the engine compartment. However, they can find places in the middle or back of the car. An open hood is also an invitation for non-rodent pests—humans—to steal car parts. It's also a bad thing to do with high winds.

4) Remove pet food and garbage from around your car. This is a good common-sense practice. However, I have an oak tree that drops acorns close by.

5) Wrap your car wiring with pepper-infused tape. This is actually sold on the market. Few people will ever do this. Even if they do, the wires will only be wrapped under the hood and not along the wiring harness that goes to the rear of the car. 

6) Park the car in the garage. This did help keep the rats and squirrels out of the cars, but mice were still present.

Ultimately, it's best to block rodents' access to all entry points into the car. A weighted vehicle cover prevents rodents from accessing the vehicle.

Ken Huening is the inventor and CEO of CoverSeal. An avid collector of exotic and classic vehicles, Huening has experienced rodent damage on more than one occasion.