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Mice in Air Filters

I live in a rural area and keep my car outside under a carport. I’ve been plaqued with mice living in my airfilters and recently have noticed them making incursions into the interior of my 2010 Prius. They’ve taken kleenex from my passenger seat to add to their nests. I’ve tried to trap them, and it isn’t working. Is this very bad for my car? What can I do about this?

There is not much you can do unless you can park the vehicle somewhere else. This can be very bad for your car if they start chewing on the wiring bundles and other components. This can get very expensive very fast. Squirrels can also be a problem but they can’t enter the vehicle interior as quickly as a mouse can. I have heard of people putting mothballs and/or charcoal in their vehicles but I just don’t think they are very effective.

I recently went through this. They’d keep chewing up every new air filter I’d put in there.

You can use things to temporarily “deter” them, such as red pepper, mothballs, dryer fabric softener sheets. But the only way to permanently stop them is to kill them with something like Decon or those sticky pads.

See if a local garden center sells a product along this line.,default,pd.html


Let me tell you about this! I too live in a rural area and park my Prius in the garage. I park next to where I store my wild bird seed in enclosed containers.
I began hearing a sound, like the crunching of leaves, every time I turned on my air. After awhile, I asked my husband to check out my air filter. We found pounds (yes, literally pounds) of bird seed stored in my air filter. Guess who? This burned out my fan that moves the air in the car. It had to be replaced at great cost due to the location of the fan. What a mess! Beware! Check the air filter frequently!

traps baited with peanut butter work. If you use live traps they must be released at least a mile from your location or they will return.

It takes some work, and you need to build a small corral around the car. But this works- have had a Prius in the corral since 1997- one mouse when we forgot one night to put it up. Here is a description of the corral:

Maybe you could try fastening 1/4 inch steel wire screen over all the fresh air intakes. 1/4 inch wont restrict air flow but will keep rodents out.


I’ve lived in the woods for 20 years and only since getting my first Camry in 2007 have I had this problem. (Well, a mouse did make a nest in a lawn mower engine once.) In the past three years I have had rodents chew through windshield washer wires and hoses, turn signal and headlight wires, and turn my cabin air filter into their personal larder for storing hands-full of nuts and dry dog food. Now they’ve figured out a way to get into the cabin of the car and I can’t figure out how/where. I would love to block their entrance because I am still trying to get the smell of dead rat out of the car after finally relenting and using a block of poison under the front seat (the rat ended up dying in the back seat during a day that hit about 95 degrees). This rat couldn’t have squeezed through an air vent - it wasn’t a little field mouse, it was the size of a Coke can not counting the tail. But in one weekend of not driving she had set up a home, stolen hand lotion, kleenex, 3/4 of a can coozie (chewed into small pieces - I found a few), and I guess was building a nest (although I’ve never found all that blue can coozie foam).

Build an enclosed fence area around your car, and buy a cat. Maybe two or three.
When you park the car at night, put the cat(s) in the cage with the car.

Now, you won’t ever have a mouse problem again, but you will have foot prints on your car’s hood and roof.


This is an old thread, but an ongoing problem that I am going after. My wife contracted hantavirus pulmonary syndrome and it was almost certainly through her car air filter system. There were repeated infestations and we could not keep them out. That is the only source we can think of that she had more exposure to than I did (I didn’t get it). That’s not proof, but is strongly suggestive, along with other information I’ve developed that this isn’t just a hypothetical problem.

I’d be inclined to cut a piece of 1/4" metal fabric or expanded metal to the size of the filter and put in in the cabin filter box with a new filter. That would at least stop the mice from using the ductwork to travel through. If you can find where they’re entering, you could use the same approach with that pathway. Metal fabric will act as a barrier.

Considering your wife’s condition, I’d even be inclined to remove the cowling cover (the part at the base of the windshield where air is drawn in) and putting a layer of 1/4" metal fabric under the whole thing.

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Stop pushing your personal website here. It’s not allowed


@cdaquila Hey Carolyn, look at ( mwaterb ) and use your magic wand if necessary.


Yeah from mouse urine. This came to light at work about 15-20 years ago, especially in warm climates and people sleeping in tents, cabins, and so on with mice are at risk. Very dangerous.

Really importing snakes would be better or cats if Tester’s method doesn’t work. But really in this day and age, what’s wrong with building a garage with tight doors?

The other day I saw a picture of that 5 gal pail of water with a ramp going up to it. A plastic Coke bottle on an axis is placed over the water and gobs of peanut butter on the center of the bottle. Mickey goes up the ramp, walks on the bottle to get to lunch and the bottle rotates and deposits Mickey in the water. Yeah its a dreadful death but what can you do? It can hold lots of dead mice before you have to empty it and add new water.

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I removed the link to the site but left the rest of the comment in.


Look for “Cab Fresh” a natural product that smells pleasant, if you like the smell of fir trees, and repels mice.
I buy mine from Amazon, works great, and I prefer the smell of that in my trucks, over the fake perfumy air fresheners.
The stuff comes in handy potpourri-like pouches.