Why Are Rodents Chewing Car Wires?

Rats love dark, enclosed spaces and the engine compartment of your car is their dream home. Once inside, they can cause widespread and extensive damage to your engine, primarily by chewing their way through wires and cables. This can not only be incredibly expensive to fix but may even become dangerous if you try to drive your vehicle in this condition.

Surprisingly, this is quite a modern problem. Rats have always chewed wires, but rodent damage to those in car engines has become far more common in recent years; the question is, why? Car manufacturers have begun to switch out certain materials (such as petroleum) in favor of more environmentally friendly materials. As a result, the wires of many newer cars are encased in soy-derived materials which are not only edible but also highly enticing to hungry rodents.

So, how can you keep rats and mice out of your engine compartment to save yourself the hassle (and expense) of a trip to the mechanic?

Why and how do rodents damage car engines?

Rats can wreak havoc in the engine of your vehicle, primarily by eating their way through the casing of wires. This can leave the wires exposed or may break them altogether, leading to electrical faults in the engine and car breakdown.

Even if they leave your wires alone, rats can damage your engine by littering the compartment with bits of food and nesting material. These can heat up when the engine is started, creating a fire hazard.

Keeping rats and mice out of your engine compartment is the best way to prevent this from happening, but why are they attracted to the wires in the first place?


Why are rats chewing your car wires?

Rats cause extensive damage wherever they go, and this is because they must gnaw and chew constantly to keep their teeth in check. The incisor teeth of rodents never stop growing and must be ‘filed’ down to stop them from getting too long. As a result, rats chew everything in their vicinity, and wiring material is particularly good for their teeth.


Even so, when it comes to the wiring in the engines of cars, rats are undeniably drawn to newer models. This is thanks to a shake-up of the materials used in the manufacturing process, as companies such as Honda and Toyota begin to abandon petroleum-based products in favor of more environmentally sound options such as soy-derived wire casing. Unfortunately, soy is a plant-based material and, therefore, counts as food to rodents.

It’s no surprise, then, that rats are chewing car wires. The real question is, how can you stop them?

How can you stop rats eating your car wires?

If your car engine has been manufactured using soy-based parts, you need to take strong preventative measures against rodents. Rats and mice can cause serious damage to your engine otherwise, and the repair bills can be eye-wateringly high!

Use essential oils

Certain essential oils (such as peppermint and eucalyptus oil) can be used as a rodent repellent for your car engine, as the smell of these oils has been found to effectively deter rats. Using a cotton bud, apply the oil to the wires in your car engine, and spray some around the hood and front wheels of your car. Do this regularly to keep the scent fresh and to discourage rats and mice from making themselves at home in your engine compartment.

Block up entry points

Inspect your engine compartment for any cracks and gaps that could serve as an entry point for rodents. All holes (even tiny ones) should be sealed to reduce the likelihood of rats and mice moving into your engine. This can be easily done using wire mesh, and can effectively protect your wires if done thoroughly.

Leave the hood down

Leaving the hood of your car up for long periods of time is, obviously, a bad idea if you’re hoping to keep rodents out. The dark, cozy, soy-rich habitat inside your engine compartment is very inviting to rats and mice, and they won’t hesitate to hop inside if you make it easy for them to do so. Keep the hood of your car down as much as possible and never leave your vehicle unattended with the hood up, especially if you’re parked in an area that’s likely to have rodents living nearby.

Lay traps and poison as a preventative measure

If you know or suspect that there are rodents living in the area where you routinely park your car, place a few traps or bait around the front wheels at night.

This can be an effective preventative measure against rats and mice that come to investigate your vehicle, and can also prevent an infestation from developing in your garage.

Keep your parking area clutter-free

Unkempt shrubs, long grasses, old furniture and recycling, and trash cans are all common harborage sites for rodents. If there is a lot of clutter around your usual parking space, it’s a good idea to have a clear up when you bring your new car home. This can reduce the likelihood of rodents hanging out nearby which, in turn, makes them less likely to infiltrate your engine compartment.


Rodents can cause significant damage wherever they end up, especially when they find their way into your new car’s engine compartment. Newer car models often incorporate soy-based materials into their wire casings, which makes them a highly attractive food source to rats and mice. If rodents start eating your car’s wires, this can lead to serious electrical faults and a hefty repair bill. Keeping rats and mice out, therefore, is essential for preserving the functionality of your vehicle! Leave the hood of your car down, clear unnecessary clutter from the vicinity of your parking space, lay a few traps and use a rodent repellent (such as eucalyptus oil) to discourage rodents from attacking your engine.

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