I've watched them do every sort of tightrope, balance beam and tumbling routine to get to their goal. They are amazing and totally undaunted.
I have an old spring action BB gun I picked up from Walmart many years ago and it's not powerful. I've been out on the deck and told my wife to watch the squirrel about 20 yards away. I'd take a shot and hit him, and could clearly see the BB bounce off him as the squirrel turned, gave me a dirty look, raised a middle finger and ran off. (Now they get even by gnawing my recycled soda bottle deck furniture.) Karma.