I have been doing this for a long time. since i was a boy. It really does work good in the fall although most think I'm crazy if i talk about doing it. From lost birds to whole flocks they will respond and I've found it best when you have a whole fock with a few talking back to you to kee kee the exact notes they do to you. Singles and doubles seem to come in fairly quickly whereas the larger groups slowly work around to you taking their time. I killed a henn this fall with my bow in september and kee kee'd them back twice after taking the first bird. They came within 20 yards three times all together but we can only take one bird a day here in ky so i just messed with them to see how many times they would work back in. I'm almost certain they thought they were hearing the bird i removed previously so were sure she was calling them back.