Im all for shooting innocent animals anytime but that isnt gonna fix the hole in your shed. I heard that peppermint oil on cottonballs will keep rodents out without an annoying smell. I have a single stroke pellet gun that I bought at one of those cummins tool sales for 20 bucks...that would probably kill a squirrel or at least hurt him enough to ask you for a couple tylenol.
http://youtube.com/watch?v=9vqLomvFjRg
Check this out but dont have any liquid in your mouth your not willing to wipe off your monitor. Jim