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Rats in your car engine: what to do

In the colder months, rats will look for a nice warm place to nest, and your engine bay is the perfect dark, enclosed shelter away from the wind and rain. Rats are also attracted to some of the materials in the engine bay because they treat some of the newer plant-based biodegradable materials as food sources.

You are more likely to be a victim of this if:

  • your vehicle is used infrequently
  • you live in an area with a high density of rats, and therefore a possible shortage of good nesting sites for them
  • you leave food in your car
  • you have a rust hole that allows access to the interior of the vehicle

How do you get rid of rats in your car engine?

Rat’s nest shown in the middle of the engine in a vehicle that is used relatively frequently

The first stage is to check the whole vehicle for evidence of rats. While they are most likely to be in the engine bay, they could also be in the boot or the main passenger compartment. If they are nesting behind the dashboard, you may need to get professional help.

Second, make the car safe by disconnecting the battery. If it’s an EV, there is potentially much more risk because of the high voltage (400-800V), and you should contact a mechanic that specialises in EVs if you suspect there could be damage to wiring.

Now you can disinfect the area as rat droppings can carry bacteria that are harmful to humans. Wear a mask and gloves. This can be done by spraying it with a bleach solution or disinfectant until it’s very wet. After 5-10 minutes, wipe up the nest materials, urine and droppings. Clean the surrounding area with a disinfectant. Don’t use a pressure washer as this could spray rat urine and faeces into other areas.

Once you have cleared out the debris you need to assess the damage. The rat may have chewed through electrical wiring and created a fire risk, for example. They might have blocked air filters or drainage holes. You may want to get a mechanic to check everything is safe.

Rats have chewed through the wiring casing. This is to create bedding materials or to wear down their teeth which grow all the time

How do you stop rats from reinfesting your vehicle?

Once you have cleaned everything, you’ll need to repair any damage, then use some rat-reduction techniques (traps, poison and/or deterrents/repellents) around your vehicle.

Clean up the area around the vehicle so that rats are not attracted to the area; don’t give them places to hide. Rats hate daylight, so you can also leave your bonnet open (assuming it’s safe to do so); eventually, the combination of techniques will reduce the attractiveness of your engine bay to rats.

You can also try a weighted car cover if you are not likely to be using your car for a long period of time. This creates a heavy skirt around the car that is difficult for animals to get under.

Avoid parking right next to your rubbish bins or other places that attract rats.

If you park in a garage, don’t store food in there.

If you notice a bad smell coming through your vents, it might be that a rat has died in the engine bay or (worse still) behind the dashboard. In this case, you may need to broaden the area you clean, plus leave your car to air out.

Thanks to Vinnie Green at TR Driver Training for the images.

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Darren has written over 3000 articles about driving and vehicles, plus almost 500 vehicle reviews and numerous driving courses. Connect with him on LinkedIn by clicking the name above

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