There are two squirrles in my garage, at first it was one to whom we gave the name "Soffit", as that's where we presumed he came through. Then a friend came. I squirted WD40 into a corner where he usually goes when he wasn't there, so that he wouldn't sit up there. To my luck he brings a friend.
I would leave some tasty coolant up there but frankly, they don't bother anyone... probably kill mice, and they never hurt no body.
I think moth balls are gonna have to do this time. Thankfully I don't leave food in the garage so that they can have a stab at it. That would bring them down to ground-zero, and then from there it's coolant fest and acidic RTV silicone to munch on as a Last Supper.