Why Rats Love Chewing Away Your Car's Wiring

There are few things more soul-crushing than turning the key in the ignition and being met with either a cacophony of warning lights or, even worse, absolute silence. You pop the hood and find a scene of pure carnage. Wires shredded, insulation scattered like confetti, and maybe even a half-eaten acorn sitting mockingly on your engine block. The culprit? A rodent. However, this isn't about hunger — it's about dentistry.

The main reason rodents treat your wiring harness like a chew toy is because a rodent's incisors grow continuously throughout their lives. If they don't constantly gnaw on things then their teeth can grow so long they can't eat, and it just so happens that the wires nestled in your engine bay have a texture not unlike the twigs they'd chew on in the wild. A warm, cozy engine bay? That's a five-star rodent resort with climate-controlled lodging and complimentary dental work included. If you're storing your car for a while, you'll need to take some precautions unless you want it doubling as a rental for some unwelcome tenants.

This is where soy enters the chat, because when you think of durable automotive insulation, you definitely think "bean byproduct." Some automakers, in a quest to be greener, switched to using soy-based compounds for their wire insulation. This has sparked a firestorm of consumer complaints and class-action lawsuits from owners. The problem is, as satisfying as it is to point blame, there is no conclusive scientific evidence proving soy is more attractive to rodents than the old-school stuff. So, while your car is dead, the debate is very much alive, as are the electrical gremlins that now call your engine home.

So, you've found your wiring harness looking like it went through a cheese grater. The repair bill is going to sting, but there is a silver lining — your car insurance likely covers it. This particular brand of vehicular violation typically falls under comprehensive coverage. That's the part of your policy that handles all the fun, "other than collision" disasters like theft, falling trees, and damage from animals.

First, you have to actually have comprehensive coverage. It's usually optional unless you're leasing your car or have a loan on it. Second, you have to pay your deductible. If the rodent-related repairs cost $600 but your deductible is $500, your insurance company is only cutting you a check for a crisp Benjamin. For some, it might not even be worth filing a claim depending on the deductible for your policy.

Now here's where it gets spicy. Insurance can deny the claim if they decide you were negligent. Let's say you noticed a small nest forming under the hood — maybe saw some droppings, and just kind of hoped the problem would solve itself. If the insurer gets a whiff that you ignored it, they could argue the damage wasn't mitigated but instead a result of you failing to maintain the vehicle. Suddenly, that massive repair invoice is doing its best Stevie Wonder impression: signed, sealed, delivered — I'm yours.

In the eyes of the automakers, an animal chewing your wires is no different than a bird leaving a present on your hood — it's not their problem. They argue it's not a defect in materials or workmanship, and they've successfully defended this in court in the process of getting class-action lawsuits thrown out.

However, while publicly denying that their wiring is a rat-magnet, some manufacturers offer a "solution." Honda, for one, will happily sell you some Rodent Deterrent Tape. It's essentially just electrical tape treated with capsaicin, the thing that makes peppers spicy, to make it unpalatable to furry friends. So they researched, they developed, and now they market a product specifically to stop rodents from eating parts in their car. There's a problem, even if they won't admit it on paper.

Losing the rodentia lottery in a regular gas-powered car is bad enough. On a good day, you might just lose your windshield washer pump or a dome light. For EV owners, a little nibble can be catastrophic. This highlights the unique peril for electric vehicles. In a highly integrated EV, a severed connection in a critical harness can brick the entire car, leaving it as mobile as a garden gnome. Let's hope that massive field of unsold Teslas baking in the Northern Florida sun is spared this death by a thousand nibbles. One curious squirrel has the potential to make Jalopnik headlines for a week.

So yeah — your car might be a rat's idea of a snack bar, and the folks who built it don't really care. Until automakers stop pretending this isn't happening, it's on drivers and their insurance to deal with the fallout. In the meantime, maybe skip the chili tape and just adopt a garage cat.