Getting mice in your car or truck can be an enormously stressful. Not only do you feel violated by these unwanted intruders, they are a significant health hazard and can cause extensive damage. If left unchecked, the offensive odor they leave behind can be very difficult to eliminate. Let’s explore the various ways to prevent mice from getting into your car or equipment and also offer tips on how to proceed if you have the misfortune of experiencing a mouse invasion.

How to Tell If Mice Are in Your Car or Garage

Mice may be quiet, but if you know what to look for, their presence leaves plenty of clues. The main hint is droppings. Study these images of mouse droppings and always be on the lookout for them in your car interior, engine bay and garage. Other telltale signs include shredded tissues, paper or upholstery materials.

Car Interior
Using a flashlight, inspect the dash, under the seats, in the glove box or storage areas, rear window sill, cup holders, door handles, the trunk and spare tire area.

Mice can move seamlessly between the trunk, interior and engine bay, so never assume that they are confined to one area. Their ability to seemingly move through walls can’t always be explained, but be forewarned that they can and usually will.

Engine Bay
The engine area is usually the first place mice will set up camp before moving to the comfy confines of the interior. The engine bay is an easy place to enter from the underside of the vehicle, so once your car catches their eye, they can be roaming under the hood in seconds. Again using a flashlight, inspect the complete engine for droppings or any other chewed up materials that look out of place. Mice will also leave tiny tracks in the dirt and dust of engine area. You can actually spot little claw marks in the dust. Mice will sometimes snack on the dead bugs stuck in the radiator fins. When this occurs, you will often see “bug leftovers” on the ground directly beneath the front grill. A common nesting area is in the air filter housing. This should be the first place to check if you see evidence of mice in any region of your vehicle.

Inspect shelves, window sills, cardboard boxes, work benches and even items stored in the rafters for droppings and evidence such as shredded plastic or paper. If there are mice, they will leave their mark.

What to Do If You Find Evidence of a Mouse Invasion

Do not put getting rid of mice on a “to do” list. Mice can do tremendous damage and as their droppings and urine can leave behind problematic odors, you must act immediately. We have witnessed situations where mice have left their unmistakable odor in classic cars that could never fully be eliminated. Also do not assume that only one mouse is at work.

Step One: Set Traps
Standard “snap traps” are just fine. As mice must be stopped immediately, this is the most effective way to bring an abrupt end to their activities. Do not fret about using inhumane methods as mice are a health hazard and can damage your property in short order. If you don’t have the stomach for this, find someone who does. Mouse traps are inexpensive and can found at any hardware store. Our favorite bait for traps is peanut butter.

In your car, set traps in the trunk and several locations in the interior. If the car is being left overnight, set traps in the engine bay as well. If the mouse (or mice) is still in the car, you will bag them in short order. The same applies in your garage. Set traps on shelves, window sills and work benches. Do not set traps where children may access them or where unsuspecting family members or car passengers could be injured.

Step Two: Clean Up
That is an article in itself, so here is an excellent article on the subject of mouse cleanup.

  • As your car’s interior can be sensitive to certain detergents, you’ll want to test an inconspicuous area first.
  • You may want to get the interior professionally steam cleaned.
  • Do get an effective mask for vacuuming up droppings. Hantavirus is very serious stuff, so do take precautions.
  • If the mice get behind your dash, you may need to seek professional help to disassemble and clean that area.

How to Deter Mice from Entering Your Car or Garage

Let’s start with the garage. Make sure to seal any holes or cracks that will allow a mouse to sneak in. Remember that mice are quite flexible and able to squeak (pardon the pun) through holes that are just 6 millimeters wide. Obvious measures include keeping doors and windows closed. This is especially critical during the fall season when mice are actively looking for cozy winter homes.  The seals on overhead and man-doors should be thoroughly inspected.

As for the car, refrain from parking in tall grass. Mice love tall grass as they can avoid being spotted by predators. Do not leave snacks (such as chips and nuts) or trash that could attract pests.

About Mouse Poison

Mouse poison can be very effective, but our opinion is that it is not suitable for automotive or household use. The first reason is that it not safe to keep when pets or children may be present. Secondly, if a mouse consumes the poison and chooses the area behind your dash as its final resting place, you may not appreciate the odor when you crank the heat this winter.

The Many Myths of Mouse Deterrence

Do mice hate certain smells?
There are plenty of old wives tales suggesting the mice will not enter an area if a certain scent is prevalent. These could include mothballs, apple cider vinegar, Bounce fabric softener sheets, Irish Spring soap, peppermint and the list goes on and on. We know for a fact that each and every one of these scents will not faze a hungry mouse looking for a home. All a mouse wants in life is to avoid predators, eat, build a warm home and procreate. They will feed right next to mothballs and peppermint and we have seen where they have chewed on Irish Spring soap. Do not take comfort in believing that any of these items will prevent a mouse invasion.

Electronic/Ultrasonic Mouse Repellent Devices
The idea behind these devices is that they emit a noise in an ultrasonic frequency that allegedly wards off mice. Pest experts will tell you that these units are proficient at removing money from your wallet, but not for keeping mice away. Again, keep in mind that everyday is a life and death struggle for a mouse, so an unpleasant noise is not going to stop them if your car or garage is a potential safe haven. We actually purchased one of these after a mouse got into our garage two years ago. We haven’t had mice since, but we haven’t had visits from vampires or leprechauns either, so perhaps these units keep them away as well.

So to sum up, always be on the lookout for clues and if you have mice, act quickly!