I have 6 hens and 4 ducks in separate coops/runs. In fact the ducks are even separated into a drake/duck pair and two male Pekins b/c the Pekins try to mate with the duck and she objects! Sometimes I let them all mingle together if I'm cleaning out the coops but it doesn't take long for the boys to start fighting so I have to at least bring the female in the run with me. Today I had the chickens in the yard foraging as well when two of the drakes started to fight. One of my chickens, Cornelia Marie, just rushed right over and cuffed them both, breaking up the fight! Those drakes were very surprised! What you need to know about Cornelia Marie is that she has had two crop surgeries and routinely wears a birdie bra. So it was some sight when my chicken wearing the birdie bra rushes over to break up the duck fight. It was a new one on me!