rat and varmit chews
I have experienced the same and we ended up using a spray that detered them. Seems like we went to a pet or farm supply store. I understand it does not taste good to them. It may be the same stuff that you use to keep a puppy from chewing. I can't remember, but it seems like there are some home remedies also. In the Telephone company and alarm business it is not uncommon that rats and varmits eat insulation. It's rather hard to know where the critters are gonna make a meal of insulation, so In the past we have placed Tom Cat poison bait. They eat it and it makes them very thirsty, they go looking for water and die.
I had a rat make a home in an engine compartmant of a F-350. He chewed on everything including the air intake. My mechanic says he's see them make such a mess that the nest in an intake is sucked into the engine. What a disaster.
My latest problem is snakes in my Backhoe. Not that they can cause problems, but we have some poisonous snakes here and I need no surprises.
If I can find the nake of that chew deterent, I'll post it here.