maybe try setting up some clay birds in trees and stuff, or have someone set them up for you, then walk through and shoot at them. The shooting shouldn' t scare the squirrels too much even if you do it where you' re going to be hunting. Leftover shotgun shells work good for this too, you can stick them on the end of branches. If they fall down, usually it would be a kill shot but sometimes you just hit the branch...just go check them to see if you hit them or not.