We have 4 ducks and they have a lovely duck house that they WONT GO INTO AT NIGHT. We don’t get it. They just stay outside in the fenced in area (covered on all sides and safe from predators) all night. Can we train them? Their bedding is just straw and it’s well ventilated plus a couple tiny fans to keep the air moving. These chatty Cathys just want to stay up all night!