So I changed the cabin filter of my wife's 2014 Honda Accord and found this weird white stuff laying piled on top of the cabin filter about the size of a hard ball if I put it in my hand and compress it a bit. I cleaned it last year on June 28th and never saw any of it then. I am trying to figure out what it might be. It is white, soft and fluffy and I can see tiny fibers in it when I pull some of it apart but it is not a fiber glass insulation as far as I can tell. Wife did take a trip with here sister up to upper Michigan and back from Chicago land area in early August. I am wondering if it from trees or other plant life. I also discovered a mouse had been on top of the engine over the winter as there was dirt and droppings on top of the engine plastic housing directly on top of the engine but I did not see any droppings, urine, or that mouse smell in this white stuff. I believe the mouse was in the garage but there is nothing like this anywhere in the garage like this stuff. Just curious as to what it might be. I am going to check that filter again every month or so to see if any more appears. Any thoughts? Thanks for taking a look.

Do you have Cottonwood trees in your area? It looks like it may be from them.

I have not noticed any in our area which is northwest of Chicago but wondering if my wife encountered any in Michigan. She said that she did remember seeing some white stuff in the air in Michigan at one point but thought it was dandelions. Thanks for the thought and picture. I think you probably are correct.

First thing I thought was a mouse. I found some insulation in my glove box and then realized there was mouse droppings. Pulled out the cabin filter and found they had made a next above the filter with pink insulation from the house I guess. There were 2 dead pinky mice in it. I assume it happened when I was traveling for a week and then they died when I put the heat on.

Mouse nest?

I don't know what it is, but I'm pretty certain it was packed in by a mouse to build a nest. They like to chew wiring, too.

A mouse is my other thought but it seems too clean to be a mouse as there is no droppings in it, it was not matted down and some was still up higher above the filter, no urine/mouse smell, and it actually smells neutral. Not saying it was not a mouse but thinking right now it might be something else.

Edit. I take that back as dang it I found mouse droppings inside the filter pleats. Mystery solved and thanks for all the help. Going to have to clean out the garage and put some mouse traps down to see if any are left. Daughter keeps wild bird food in the garage and I am going to have to make her keep it in sealed plastic containers. Still scratching my head where the white stuff came from unless the mice took it from inside auto somewhere?

Thanks for the replies!

I suggest a 10 gallon galvanized steel trash can with a tight lid. Ace hardware or True Value hardware sells these for around $20. Behrens makes a good one.

The little rodent bastards can chew through plastic very easily.

I bet the white stuff is insulation from the heater duct. Mouse nesting material.

Possibly padding from some kind of furniture, indoor or out. Mouse house.

Two days ago get in my 2017 Camaro and smell DEAD mouse. Hadn't driven it in about 5 or six days.

Mouse had gotten in through the cabin air filter door...made a nest on top of that filter, then either died, or had babies and they died? Anyway....Somebody is dead behind the dash.

Bought one of those little inspection cameras today, hoping to see behind the panels just what I have and if I can fix this mess myself. No joy! Simply no room to get in and retrieve anything. Off to the Dealer to take care of it.

My insurance will cover the fix, short of my deductible. Fucking mice.

quote:

Originally posted by FN in MT:
Two days ago get in my 2017 Camaro and smell DEAD mouse. Hadn't driven it in about 5 or six days.

Mouse had gotten in through the cabin air filter door...made a nest on top of that filter, then either died, or had babies and they died? Anyway....Somebody is dead behind the dash.

Bought one of those little inspection cameras today, hoping to see behind the panels just what I have and if I can fix this mess myself. No joy! Simply no room to get in and retrieve anything. Off to the Dealer to take care of it.

My insurance will cover the fix, short of my deductible. Fucking mice.

WOW that really sucks, hope you get it resolved soon. Sounds that top of the cabin filter is a favorite place for mice to nest inside an automobile.

quote:

Originally posted by arfmel:
I suggest a 10 gallon galvanized steel trash can with a tight lid. Ace hardware or True Value hardware sells these for around $20. Behrens makes a good one.

The little rodent bastards can chew through plastic very easily.

I bet the white stuff is insulation from the heater duct. Mouse nesting material.

Thanks for that advice and I will look at those. I know that for pest control cutting off the food supply goes a long way to eliminating the problem.

+++ on the steel can. I used to store my seed in my garage in a plastic containers. Mice gnawed right into them.