Been awhile since I was on the BBS so I thought I'd kick in with a suggestion for DC or any chemical engineers out there. How about a spray or material that causes rodents (aka rats and mice) to croak when they nibble the firewall or other insulation? I've got about one square foot of firewall insulation left and the varmints want that for their nest or whatever. I've tried everything (smoke bombs, fake owls, mothballs, D-Con, . 22 rifles) and the best solution is a big rat trap sitting on top of the engine. But raising the hood and moving the trap is a pain. Yeah, I know, I could close in my carport but that won't work either for other reasons. I think a poison material sprayed on or bonded to the insulation would do the trick. Any ideas?