I have the same squirrel call as Shadow and it works great. I also picked up a different kind this past season, I'll post a pic of it later, and it a great call also. The new call I got is actually 2 calls in one as you can also make the very useful young squirrel panic call. The other thing it does is it has a feature where if you shake it quickly it actually perfectly mimics the "chatter" call.
There are plenty of times I've spotted squirrels that were out of range or moving off in the opposite direction and when I start calling they stop and start working their way towards me. Doesn't work all the time but it does work most of the time. Besides giving you more shots at game it also, at least for me,,,, adds to the challenge and enjoyment of the hunt.....
OH,, I forgot to add,,,,, last year after reading some articles on eating crows I gave them a try. I have to say,,,,, they were very good. I'll be eating them again if and when I bag some more :)
Jeff