I think I have read on here that in Disney's Animal Kingdom the animals are put into their barns every night. If this is true, how do they coerce animals like hippos into a barn and how do they get birds in for the night?
They are called in with individual sounds, which I'm sure takes a great deal of time and patience.
I could see that actually working because in our children's zoo, the chickens and turkeys used to be trained to come in at the sound of the whistle. I don't know if we still do it.