Rats! Something is chewing the wiring on RVs, tow vehicles and dinghies!

Yes, rats, quite literally—or more likely mice, and maybe squirrels, rabbits or groundhogs.

The wire-chewing problem appears to have reached epidemic proportions. Ask any insurance agent and you’ll hear that claims for chewed wiring are rising. Online reports of damage are widespread. One woman complained to the National Highway Traffic Safety Administration that when she turned on her car’s air conditioner, mouse fragments rattled around the box fan and flew everywhere through the vents, including all over her. One Toyota Tundra owner has sued Toyota over repeat episodes of rodent damage to under-hood components.

Comprehensive insurance usually covers the damage, but owners are left covering deductibles that can reach $1,000 or more, depending on the policy, and they lose the use of their vehicles until repairs are completed.

A Matter of Taste

Rodent damage is nothing new, of course. Mice have always found a way to squeeze through the tiniest opening—or chew their way through anything but stainless steel—to reach any food not placed in a sealed container.

But that was all kinds of food. What has made rodent tastes go from eclectic to electric? Why have vehicles become all-you-can-eat buffets for rodents?

They’re attracted by the new coatings on automotive wiring. Once protected by a rubber-based product, and then by petroleum-based plastics, the wires are now increasingly encased in a more environmentally friendly soy-based sheathing.

And rodents love it. To them, it’s food. Automotive wiring manufacturers might as well have posted blinking neon signs in driveways and campsites that say “Mouse Diner This Exit.”

What Can You Do?

Short of poison, it is possible to keep rodents from wiring, but it’s not always easy.

Avoid resorting to poison. It can work, but it presents dangers to people and pets. The rodent doesn’t die where it eats the poison, but instead where it is when the poison takes effect. That could be inside a wall or air duct, where the odor can linger for weeks. In ductwork, it will not only smell, but also can spread the poison through air conditioning and heating.

If a pet eats a poisoned rodent—lying in a corner of your coach or on the ground outside—the pet is poisoned, too.

It’s a better practice to keep rodents away from the wiring.

Here are some things that can help:

• Have metal screening installed around wiring under the hood of vehicles, and over vent openings. Screen is cheap, but the labor to install it may run into hundreds of dollars.
• Wrap wires with an electrical tape that repels rodents. Honda 4019-2317 electrical tape is infused with capsaicin, a hot spice that will convince a mouse to dine elsewhere. You can install it yourself when the engine is turned off and cool.
• Spray wires with a rodent repellent, such as Rodent Defense or Natural Armor Vehicle and Engine Protection. They don’t kill rodents, just ward them off.
• Mouse Free is a spray applied to the underside of any vehicle with a compressed air sprayer before and after winter storage. It contains natural oils, including peppermint, which rodents hate. It’s not cheap, costing a bit over $100 for a gallon and sprayer. Refills are around $35.
• To catch mice, set snap traps around tires when your RV, tow vehicle and dinghy are parked. You’ll need three traps per wheel—one in front, one in back and one on top. That means 12 to 18 for a tow vehicle or motorhome, six to 12 for a travel trailer and 6 more for your dinghy.
• Plug any holes in your RV, preferably with steel wool, which mice can’t chew.