My chicken and duck runs are side by side with a door to the chicken run inside of the duck run. Every day hens will fly up to sit on the door and just stay there. They'll turn around to watch the ducks but none of them have ended up in the duck run. They probably know they'd be in trouble if they did! They don't even jump down outside of the duck run into the grass which they easily could. We used to swat them down but we don't bother anymore because they never stay up there longer than 10 minutes. Crazy birds! lol