I have two silkie hens that are sitting on nest all the time, night and day. Problem is there are no eggs in the nest they are sitting in. The eggs are always in another nest. Why would they be sitting on empty nest when there are eggs to sit on? I've been taking them out when I get home from work and making them walk around and eat. One of the hens just sits on the ground with her butt in the air and her wings fluffed out for about five minutes and then off she goes. Ten minutes later they are both back on empty nest. Any suggestions?