This may seem somewhat of an awkward topic, but knowing how to keep animals out of your car engine may come in handy.

Either it’s a household pet, stray animal, or pesky rodents, the last thing you want is this problem.

Messy accidents, damaged wiring, awful smells from the ventilation are just some of the outcomes if you don’t notice and solve the problem on time.

In this article, the main focus will be on cats and rodents as these perhaps cause the most problems. But perhaps you can find tips that may be useful for other animals also.

At the end of the article, you also have a YouTube video tutorial.




To learn how to keep animals out of your car engine, now that prevention is one of the best ways.

Spotting the problem on time and taking action before anything bad happens is the best scenario.

Once you open the hood (bonnet) to check the oil, for instance, you’re bound to take a  brief look around the engine bay. If an animal is or was present, you’re bound to see it.

  • For cats

Sure tell-tale signs will be traces of paws and fur. Look for traces on the engine cover, behind the engine, under the engine, or any other convenient or big enough part of the engine bay.

Cats usually crawl inside the engine bay during the winter season as they seek shelter and a way to keep themselves warm. If a cat is allowed to do this, it will make a habit increasing the possibility of an accident.

  • For mice, rats, and other rodents

Traces of straws, rags, or perhaps little pieces of plastic bags are a sure sign you have a rodent problem. Rodents use these for making nests.

Check the hidden and secluded places in the engine bay like the wiper mechanism compartment, fuse boxes under the hood, pockets near the headlights, the plastic casing for the battery, and so on.

Also, you may encounter nibbled or damaged wiring installation, rubber seals, plastic parts, or else. If you see this, tend to the problem immediately so it doesn’t cause any further damage (like short circuits, leaks, or else).

One more obvious sign is a strong odor coming from the ventilation system. Mice tend to find their way inside it and die there. The strong smell of decay eventually gets to the passenger cabin.

So, if you change the cabin filter, disinfect the ventilation system and there is still a foul smell, you might want to start searching for this.

A definite sign that you have a rodent problem is feces all over the engine bay or inside the passenger cabin.

Making regular checkups is something a lot of drivers don’t have a habit of doing. For learning more about check-ups you can watch our YouTube video or visit the page dedicated to that.




As mentioned, animals have habits and needs and act accordingly to them.

With some luck, you’ll be able to spot the animal running to or from the car.

They will have to leave their shelter in search of food so sometimes take a glance (just a minute or two) and see if you can spot the animal.

On this part, I would also like to mention that small puppies have a nasty habit of curling behind the wheel making them almost invisible. If you have one and it walks around freely, take a look before you start driving.

Bigger animals are, of course, easier to spot, rodents are somewhat trickier. Nevertheless, if you pay attention you can catch them in the act.




Pretty basic tip but very effective, especially for larger animals like cats, squirrels, or even dogs.

Before you start the engine and start driving, honk the horn two or three short times.

Animals don’t like strong and unexpected noises and if there is one it will surely run away.




Same principle as with the horn. The strong and sudden sound of hitting the hood should certainly drive the animal away.

Do this before starting the engine or driving, best before you enter the car.

Don’t use too much force so you don’t damage the hood. Rather make a slight slap with an open fist.




How to keep animals out of your car engine? Using some sort of repellant is one of the best ways.

Most repellents function on the principle of having a strong odor that, when put in proper places, drives the animal away.

There are two basic types: natural and artificial.

I would recommend trying natural ones first. Most of them are widely available in most countries and are harmless.

For the artificial ones, best consult a veterinarian or an expert in the field before using any.

  • For cats

Orange or lemon peels, coffee grounds, tobacco (the one for pipes), vinegar, lavender oil, etc. All of these have a strong scent that cats don’t like.

  • For mice

Try with pepper, cloves, peppermint, or oils from any of these plants.

These strong scents tend to drive the rodents away.


One of the best ways to distribute these is by using an old woman’s stocking and filling it with one of the mentioned repellents. If you’re using oil, best to take some cotton balls, soak them with the oil, and put them in the stocking.

Leave it inside the engine bay or passenger cabin for some time. Best overnight or as long as you won’t drive the car. Just don’t forget to remove it before you start driving.

Also, if possible, leave the hood or passenger cabin open for some time before driving so the scent can evaporate.

Doing this for a couple of days or perhaps a week should be enough to drive away from the animal for good.

On this part I must mention what I did to stop the cat from resting on the engine cover: I used cockpit spray, both for cleaning and repelling. First I cleaned the engine cover with a wet cloth and used the spray. Seems the scent drove the cat away for good and the engine cover was as good as new.

Worked for me so maybe you can try it.




These gadgets are very popular both for their effectiveness and because they are pretty easy to install.

Electronic sound repellents produce an ultrasonic sound that animals find disturbing and run away from.

For cars, the sound repellant works by connecting it to the car battery (in most cases).

There are usually clamps or connectors for easy installation, usually near the car battery.

The sound, in most cases, is strong enough even to reach the passenger cabin.

Perhaps the best part is that there isn’t any odor and it’s easy to use.




Old fashioned way but if you want to know how to keep animals out of your car engine, you should have this in mind.

I would recommend the plastic mouse traps with the bate already attached. These are cheap, pretty effective, and have less possibility of causing damage in the engine bay.

You should put them in suspected pathways of the rodents.

But make sure that you don’t put them anywhere near sensitive installations like wiring, connectors, fuel lines, or else. When sprung, the trap may cause damage to the surroundings in the engine bay.

If the rodent is inside the passenger cabin, best to leave the trap in the footwells.

Again, don’t forget to check and remove the traps from the engine bay before starting to drive.

If you’ve set more than one, be sure to account for all of them. The last thing you want is for it to fall into the serpentine belt or something like that.




If you want to know how to keep animals out of your car engine, then best avoid parking near garbage cans or dumpsters.

These are some of the favorite places for mice, rats, and other rodents as they are an excellent and regular food source.

If you have a regular parking place near a dumpster or garbage can, know that it’s only a matter of time before you get an unwanted visitor.

Your car might be in their path, they may scent something in the car or may seek shelter.

What’s even worse, just one night spent near a can or dumpster can cause mice or rodents to nest in your car.

All in all, avoid parking and leaving the car near them whenever possible.




This tip is not directly for how to keep animals out of your car engine but it is connected.

From what I’ve encountered, mice and rodents in most cases like to nest inside the passenger cabin while the exit is through the engine bay.

So, if you prevent nesting, you’ll probably reduce the possibility of damage.

One of the best ways to do this is to cut the food source.

What is a good food source?  Leftovers in the passenger cabin.

Greasy wrappings, crumbs, little pieces of meat, vegetables all may give off a strong scent that will attract them.

This goes double if you don’t regularly clean the passenger cabin and leftovers are always present. Then the rodents will make a habit of visiting and feeding.

So, to avoid this, clean the car interior regularly, especially from food leftovers.

For instance, a good practice is to immediately clean the car after every takeout, especially with kids. Get rid of all the packaging and if possible use a vacuum cleaner for the interior.

Also, any kind of food/drink spilling should be tended to immediately.

If you have to clean your car interior and want to do it at home, click here for a separate article on that topic.




This last tip is from personal experience. You don’t have to necessarily use it when learning how to keep animals out of your car engine.

The story goes like this: once I loaded a protective mesh for our greenhouse in my station wagon not checking if there was anything inside. It was folded multiple times and was under the shed for days.

That made it a perfect temporary hideout for a mouse.  So, it came into the car with the mesh.

Luckily, later when I was waiting in the car for my wife I heard a weak scratching noise coming from somewhere inside the passenger cabin.

As I live in the countryside, I knew pretty much immediately what it was. So when we arrived home, I set up a few traps overnight and the problem was solved.

To be honest, I was lucky, sometimes solving the problem takes much more time and the rodent can cause damage before it’s caught.

Lesson:  whenever loading things that may contain rodents, inspect it, give it a bit of a shake, or unfold it. The rodent will certainly run away.

Do this especially if the things were stored in places where mice, rats, or other rodents may be present.



I must emphasize again that prevention is the best solution. Spotting the problem and reacting on time is the best way to keep animals out of your car engine and the whole car.

If you neglect it, know that something as small as a mouse can cause some huge damage which is both dangerous and expensive to repair.

As mentioned, these tips apply to the most common situations with the most common animals.

Other animals that are known to cause problems are raccoons, squirrels, snakes, other types of lizards or insects. In this case, it’s best to look up habits or ways of feeding for each animal to find a solution.

With more aggressive or dangerous animals don’t hesitate to call specialized services that know how to handle this in a safe and professional manner.

In the end, when it comes to situations like these, the best outcome both for you and the animal is a safe and sound parting.



Written by: Sibin Spasojevic


Former car technician, life-long car and DIY enthusiast, author for Despairrepair.com