I have had problems with them nesting in my garden tractor engines and the bastards chew all the insulation off the coil and spark plug wire (one solid state ignition on my Sears Suburban was chewed bare.luckily I was able to repair it by using heat shrink tubing and RTV --it would cost 200 bucks for a good used one IF I could find one for it!)..I also didn't discover this damage till the engine got so hot it actually caught the paint on the head and sludge on the block on fire,while I was mowing last summer--blew the head gasket and warped the head too!..--other engines I have in storage usually get mice infested too,and I have at least 6 "barn cats" my mother feeds hanging around too--they DO kill some mice,I see plenty of dead ones,but the mice must have a fetish for small engines because thats where I see them most!..
On the tractor board I frequent there has been many threads about how to keep mice out of engines and cars,garages,etc..everything from moth balls,flakes,cut up bars of Irish Spring soap,WD-40 ,Lysol,and numerous other things were all mentioned,of course everyone swears THEIR method is best,so who do you believe..one thing I would NOT reccomend is D-Con--the mice will die somewhere in your vehicle like deep in the defroster duct or heater box,and be dam near impossible to remove,and you wont be able to GIVE the vehicle away with that death smell in it that never seems to fade!..plus,the dead mouse will poison any other animal that eats it too,like your dog,cat,or other things like skunks,racoons,foxes,coyotes,etc..
My van has sat idle since 2003,and it has plenty of rot where mice can walk right in--so far though,only WASPS have infested it,I do see a dead mouse near it often,so the cats must be doing their job!--but inside the van I had a spray can of Bissell brand house disenfectant (Like Lysol,same thing really)--the can got rusty and all the stuff leaked out a few years ago,smells like a hospital in there since--but evidently mice must not like the smell because I'm sure at least one could have sneaked past the cats and made a condo out of it..One guy I know who's very smart about animals says to use a few drops of "predator piss"..but I dont really want my vehicles smelling like pee,and how would I GET a fox or other predator to pee in a cup for me??..
