Eventually the ducklings need to move in (or should I say out) with the rest of the flock. So far they go on field trips on the opposite side of the fence where the adult ducks and ducklings can all see and hear each other. Eventually they all need to be in the fence together. What are signs of aggression to look out for to indicate that it may not go well? What are signs of curiosity or that they like each other? How do you decide it's safe? How do you determine everyone is ready to mingle? Do you put all of them together or let them meet one on one? Also I feel like there is an article on this somewhere and I can't seem to find it.