When we are using the Foxpro, and are aways apart, I'll turn it to something different to signal to my son or whoever that it's time to pick up and move. Once I thought I would be funny and I went to an "elephant distress", (I bought the caller used and it came already loaded on the call), and about 30 seconds later, here one comes running wide open! My son missed, and then I missed twice more it took us by such surprise! So they WILL come to a sound they have never heard before!