I have 4 ducks. A male khaki, a female khaki, and two female runners. I've noticed that the female khaki and one of the female runners seem to be trying to sit on the eggs. In the morning it's the khaki and at night one of the runners. I keep taking the eggs. They are not mean about it. It's like they are border line broody together and sharing the responsibility. This started a few days ago. At first I thought they were sick because when they are on the nest nothing, not even treats can get them off. I would love babies but I can't take the chance of having any more boys, it just wouldn't be responsible. I am interested in what they are trying to do and it seems they are working together.