Pellet gun.
I've got a crazy cat lady in my neighborhood and for about a year, those mf'ers would come into my backyard, make noise, fight, etc.
Then one day I put a pellet in the ass of one of them, and haven't had any come around since.
It probably helped that as it scurried away I was shouting "YEAH!! AND MAKE SURE YOU TELL YOUR FRIENDS!!"