We supervised the chickens when they were young. When they ventured from our property, we would round them up and clap our hands to herd them in the direction we wanted them to go.I had no idea chickens were trainable. I learn something new every day. How do you train a chicken BTW?
We did the same thing with our indoor cats, except we just snap our fingers. We don't even have to say their name. If they hear snapping and know they're doing something "bad", they generally stop. To get the cats to stay in our yard, I snap. If that doesn't work, I say their name sternly and clap. That usually sends them running for the deck.
If a cat goes out a door and wasn't invited, I get them and carry them back in the house. Most times, I can open a slider to let our two siamese cats on the deck. I can call them back in the house just by saying their names and then have them follow me out the utility room door. It takes time and patience to train animals, but the rewards are huge.