I started using a dog training clicker on my chickens to call them over from where ever they may be. And it worked! I started with them in site and would click the clicker a few times and then throw down some treats. Slowly increasing the distance each time. After just a few days, I can go outside and without even knowing where they are make a few clicks and they come running! This really helps when I need to coop them up if I need to go out during the day.