I am completely new to guineas, and I have two keets coming next week. I was reading some articles about how to get them to come to the coop at night (when they grow up, of course!) and one said you can train them to come when called. It suggested a cowbell or a whistle to call them as they like to wander. So, my question is, if I use a whistle, can they hear a silent dog whistle? In case they go off pretty far, I don't want to make a ruckus and bother the neighbors!