The squirrels used to spend the winter in my attic, tossing around the blown in insulation to make nests, busting holes in boxes looking for crayons to eat, and waking me up early scampering around up there. I trapped a dozen of them, and every time another moved in, until I fixed the siding. In the beginning I used a paw trap and drowned them in a bucket, but I felt bad after one left a toe in the trap. I got a live trap and started relocating them to better neighborhoods with lots of huge trees. Now they can only get in during the summer when I leave the attic door open. One day I found a walnut under my pillow.
Spraying the whole engine compartment with wd40 does a pretty good job of keeping them away and makes everything look nice. They'll usually start to nest in the air filter before they start chewing the wires
