View Full Version : Mice in AC Vent ducts

greg mgm
02-01-2012, 04:50 PM
I found a bunch of mouse debris (Droppings, acorn shells, etc) sitting on top of the cabin filter in my '10 Tundra. There's no room to remove the debris before pulling the filter and I ended up having some of the shells fall onto the blower motor. It's a pain to get all the shells out of the blower!

I have a bunch of dryer sheets in the engine compartment as a deterrent, but I thought the AC vent system was closed. I have no idea how mice are getting in the venting. Anyone have experience with this?

On our '10 Jetta tdi, mice have chewed the insulation on the injector wiring harness, but not through the wires. Since we started putting dryer sheets in the engine compartment we haven't seen any indication of mouse activity.

02-01-2012, 06:14 PM
I have a bunch of dryer sheets in the engine compartment as a deterrent, but I thought the AC vent system was closed. I have no idea how mice are getting in the venting. Anyone have experience with this?

Hmmm...where exactly do you place these dryer sheets?

I've had this same problem in the past on my 1985 Toyota pickup. It was just one mouse that I picked up while camping and when I left the camp site the mouse luckily didn't come home with me. I did have to remove the vent blower and remove the nest my little friend had started to make. I'm still scratching my head as to how the mouse made it inside my dashboard.

greg mgm
02-02-2012, 01:13 AM
On the Jetta we put the dryer sheets on top of the engine cover and around the edges of the cover, towards the bottom of the battery and in the back near the exhaust manifold. We have 12 sheets in there and seems to work OK. On the Tundra I put 6 sheets on top of the engine cover so far. There's no damage to wiring that I can find. It bugs me that they're getting in the vent system. The vent system air intake is in front of the windshield and looks OK so maybe they chewed through a duct or something. There's no evidence they got inside the cab. I'll take a closer look tomorrow.

02-02-2012, 03:23 AM
I see at least a few mouse nests and debris in Lex/Toy cabin filters each week. I think they just drop in from the top, under the cowl in front of the windshield. I don't know about Tundras, but on my truck at least, the area under the cowl drains into the rear of the wheel wells. Not my pic, but this is what the drain looks like at the side of the cowl area (hopefully yours isn't clogged like this):

It's possible the mice scurry up inside the fender liner, into the area under the cowl (nice and warm there) and then drop into the duct work. If you can pull the cowl off, maybe put some "gutter guard" or similar screen over the HVAC air intake (does Community Lumber carry anything you might use? If so, tell Karen that Keith & Liz say Hi). I think this is a Taco, so yours will probably look different, but similar

Hill, Bill E.
02-02-2012, 03:29 AM
Mice can squeeze through a hole that your thumb will not fit into. Sneaky little dudes, and they love blower motor compartments!

Moth Balls work best, especially for long term storage- but the naptha smell lingers forever! (still favorable to rodent urine!)

Dryer sheets are the next best remedy I have found, but they need to be replaced every 3-4 months to remain effective.

02-02-2012, 01:31 PM
Is that why my cabin fan blower motor is squeking? The mice are getting tired of running to turn that darn wheel?

At least it's not Cockroaches. I grew up in Hawaii and we would go out to the car at night to go somewhere and when we would open the door and the dome light would come on, the roaches would scurry back under the seats. Sometimes while driving they would crawl up your leg.

As a result of that I now have an iron fist about "NO EATING IN THE CAR". But it sounds like the mice are interested in a nicve cavity with some tasty rubber to munch on.

But really, that sucks.

Time to visit the DIY exterminator store and get a permit from the State to use some serious firepower.

02-02-2012, 01:42 PM
This seriously hits home for me. I have been chasing mice in my Syncro since I got it a year ago. Previous owner lived in the High Desert of NM and quite a few field mice found a home in the AC ducts, and back seat back, etc. I have a "Thing" about rodents (and roaches, but thats another story)

I will have to try the dryer sheet trick.

Currently I'm involved in a war in the shop with what seems like an endless horde of mice and the occasional Rat, suppose its my own personal little slice of hell!

I had a mouse find its way into my wife's Scion, by hiding in my daughters car seat that was in the garage for a few hours. Nothing like tearing apart a new car interior chasing a single little mouse!

If I had roaches in the car, it would get Sold CHEAP!!

02-02-2012, 09:35 PM
What exactly do the dryer sheets do?

02-02-2012, 11:44 PM
Vector and Wal-Mart are your friends, or a lot of patience and a pellet rifle.

greg mgm
02-03-2012, 03:35 PM
What exactly do the dryer sheets do?

They have a strong scent that mice don't like, and they apparently avoid the sheets. I read that on the "internet" so it must be true. :)
So far in our Jetta, the dryer sheets seem to be working. I still have to inspect the Tundra closer...hopefully today.

FYI- My baja sits in an enclosed barn and I see mouse droppings inside the car, even with a sonic rodent repeller running inside the car.
I have a feeling the sonic repellers are a waste of money. It would be difficult to cover the interior with dryer sheets (Dryer sheet upholstery?)
I may try leaving a radio (Plugged into ac) going to see if it has any effect.

02-04-2012, 03:24 AM
Supposedly strobe lights repell them to. Wife's boss has some installed in the attic and no more roof rat issue after trying pretty much everything else.

02-04-2012, 04:08 AM
Supposedly strobe lights repell them to. Wife's boss has some installed in the attic and no more roof rat issue after trying pretty much everything else.

No. Rats hate disco.

02-04-2012, 04:26 AM
No. Rats hate disco.

Funny, first thing I asked was if they were going to install a neon floor, and if they didn't think the constant barrage of Bee Gees thumping through the ceiling was going to keep them up at night.

greg mgm
02-04-2012, 04:49 AM
Ha ha. I was thinking about leaving a radio on playing "All Polka All The Time" but maybe that would attract more rodents. :sombrero:

I can see how a strobe light could repel rodents as well.

02-04-2012, 07:45 PM
If you just want to repel them try peppermint oil on a cotton ball. It even gets great reviews on amazon. I've used it in my old Toyota to keep them out but I really like the glue traps. They even catch cats;)

greg mgm
02-05-2012, 05:01 AM
I won't do glue traps. Peppermint oil sounds good. I may try that later on. The dryer sheets so far are working good in our Jetta.

02-05-2012, 05:14 AM
Moth balls (Napthalene) is a carcinogen, iirc... don't overdo it. It will make you sick. Our office landlord's maintenance people tried to use a product called bat-a-way (basically mothballs) some years ago to remove a colony of bats (over my objections btw, better ways to do that). Anyway they dumped the container loose into the insulation in our suspended ceilings. They managed to poison everyone in the building. I had stomach issues, a co-worker had heart problems, no one could work more than a few hours a day in the building. Eventually they managed to remove it all and left the bats in peace...

02-05-2012, 09:43 PM
How is everyone getting the dryer sheets to stay in place? Just taping them down?

greg mgm
02-06-2012, 06:03 PM
We just set them in place and so far none have fallen out.
Maybe I spoke too soon about the dryer sheets. This morning there was a small pile of insulation sitting next to the dryer sheets on the engine cover. Apparently now they like the scent. :)