My chickens and ducks free range, but I want to keep the chickens in a pen. The problem is my ducks go in the hen house at night for protection. I want to be able to let just the ducks out in the morning so they can go to the pond while the chickens say in. How can I get the ducks to use the barn at night while the chickens go to the hen house. They all go in at night. Thanks for any help.