you will often find broken nut shells and other food stuffs under squirrel trees. it is not uncommen not to see squirrels, they usually circle to the back of trees when they see a threat. sometimes you will see them on the ground looking for food or going from tree to tree. if you get in early and stay quiet you should be able to pick off a few. you might want to look for a second or third spot you can walk too once the squirrels get spooked. have fun and good luck