What material was used for this nest? – Diagnostic Network (2025)

AiDN AI Assistant

This is a reply from an experimental AI-powered advisor. It is important to exercise caution, verify information from multiple sources, and make informed decisions based on the prevailing circumstances.

David, I can't view the files you attached, but common materials used by rodents to build nests in vehicles include insulation from the HVAC system, seat padding, and even paper or fabric debris they find inside the vehicle. If there's no visible damage to the carpet or material under the hood, they might have sourced it from the HVAC insulation or found loose debris within the cabin. Check…

Matt Mechanic

not sure what that is, but its not unusual for critters to bring in outside nesting materials… Just replaced a knock sensor harness twice in 3 days from rodent damage, they ate the harness twice, but werent nesting. Customer said that he found nesting under the hood of his wife's car. Apparently, they were going out to eat. Just like finding huge piles of acorns or pine cones under hoods.

William Owner/Technician

Do moth balls work to keep rodent's from coming back, are there any effective repellents. We had a relatively new toyota come in running poorly, we popped the hood and the biggest rat you could imagine was sitting on top of the motor. It took us three days to get rid of him.

Glenn Owner/Technician

Hi William,Dealing with rodents is always a challenge, never seen moth balls do anything for rodent but the smell lets people know they are there.My advice to my rural area customers is leave the hood up at night when parked at home, especially in the winter. Don't provide a warm engine bay for rodents to nest.Sticky traps are about the safest and less smelly way to catch most small mice…

William Owner/Technician

This rodent ate a block of rat poison and and a bowl of water. Did not phase him, he ate the top cover on the motor which was made of carbon which must of protected him. We left the hood up with the car outside and he would not leave. Finally using broom sticks with the car on a lift he fell out and was dispatched. Toyota must use vegetable oils for wire coatings because we have seen several…

Glenn Owner/Technician

Hi William,It's not just Toyota. Most automotive and farm equipment electrical wiring is made from the waste product of cooking oil production. Rodents think the wiring insulation and some vinyl products are a food source. It is similar process to what the petroleum industry uses to make plastics and rubber products.

Barry Owner/Technician

We use a mouse repellant tape for the recurring issues, it has hot pepper in it! Found it on Amazon. As long as you don't get a rodent that likes it spicey, it should be fine!

David Owner/Technician

Honda part number … is the pepper-infused tape, if anyone is interested.— Dave

Glenn Owner/Technician

Hi David,That tape is about $50 a roll. If you use it don't touch your face near your eyes (ask me how I know)3M spray adhesive or similar and red pepper works wonders too. A light spray of the adhesive and then dust it with the red pepper.I've used it on field tractors inside on the cab wiring a few times (sparingly). It works wonders on vehicle harnesses such as the top of a fuel tank…

Marvin Mechanic

Probably from something under their carport ..I had a 6.4 diesel air cleaner that was full of surgical gloves ..owner had been staining furniture under carport ..so many in it it sounded like giant vacuum cleaner loo

Glenn Owner/Technician

Hi David,If you pull the dash back and remove the HVAC case, you will find issues I'm fairly certain. If I am not mistaken these have 2 cabin filter that slide in one behind the other. The rodent was slipping between the ends of the two filters to find material for a nest.Looks like HVAC insulation pad or sound deadener pad material like a hood pad. That little strip of tan/light gray…

LaMont Owner/Technician

I misread the post.

David Diagnostician

Nothing in plain sight. May have to do some real work and remove the dash as Glen said.

Hollis Technician

Ask the customer if they recently shaved their back :O)EDIT/ADDED: Sorry, couldn't resist :O)On a serious note, rodents source all sorts of nesting materials usually from the vehicle. I've found they get it from the between the hood and liner with no visible signs from under the hood, firewall as well. Or from nearby sources, like fibrous outdoor foot mats, ect.I install aluminum mesh…

Ron Technician

Did you check the firewall ? That type of material is used on the firewall in the engine compartment.

Dan Owner/Technician

… David … Here is a “ BrakeRat” from my saved things over at the iATN … Gnarly looking critter {8^) ~ …lol..members​.​iatn​.​net/file/view/?id…Dan H.…Hobbs… South Texas …

Glenn Owner/Technician

Hi Dan,You remember the days of rear leaf spring traction bars? Seemed like everyone who owned a RWD sports car would slap those things on. (including me)I found out late one night they make a good stray animal catcher/killer for those ones that dart across a road when a vehicle comes through. I clipped one such animal and did not think too much about it until the next morning when I spotted…

Marlin Technician

It looks as thought it may be roof vent screen.

J. Owner/Technician

Looks like firewall insulation material? The most interesting thing that I have found was about a dozen 3/8 sized ball bearings in a engine air filter on an old carbureted engine. At least they stayed on the outside of the filter!