This summer for the first time ever we had either a pack rat or mice eating the wires in our car...Cost us around $500 before out of the blue I thought of moth balls...took a 6 in square of muslin, sewed down the side making a rectangle and filled with Dollar Store mothballs....placed them around the engine and no more wires eaten...did leave them out one night and another wire chewed...put them back and no more chewing...so I'm convinced this did the trick....I'd rather smell the moth balls than dead mice...also would rather they just stay away than deal with having to dispose of dead bodies....Pets dislike them too so no danger to them either... I'd just make enough to put around the perimeter or where I thought they might be coming in...Good luck...hope this works for you...