Calls for squirrels?

[tooldummy]

I have a couple of squirrel calls. The type you bump on your hand or gunstock and it sounds like one barking and then you can also blow into the other end and it sounds like a small one in distress. I've not had a lot of luck with them though. I made a call out of two pop cicle sticks and a rubber band a couple of years ago and tried it coyote hunting. The squirrels came running to it, but no coyotes. Tried it last year squirrel hunting, and nothing. I guess sometimes they work, and sometimes they don't. I've heard of guys using two quarters to sound like one knawing on hickory nuts, but never have tried that.