Where I hunted as a young man - it was mostly small farm wood lots and not a lot of squirrels. They were all fox squirrels, and some of them were wise old boars, that if they saw you - would duck into a hole in a den tree and stay there till you left no matter how long you sat or how quiet you were - they also ignored all calls. I thought those smart old guys were almost too wise to ever get-till I met this old hunter who walked past my house with a limit of squirrels real often. One day I got brave, and asked him how he got so many, so often. He told me this trick - and it helped me take a bunch of those smart old boogers over the years. When one of them busts you and holes up like they will. Just sit down where you have a good view of the hole and wait for things to settle down - 10 or 15 minutes - then - take a small mirror,(I use a metal GI signaling mirror) and flash the light into the hole a few times - moving it back and forth,then put it away and get ready. Usually, that old squirrel will come boiling out of there spoiling for a fight and chattering like crazy and an easy shot if you're ready. Of course - this only works on sunny days.