I was hoping they would mingle with no problem! Urgh! I let the 2 older hens free range so I could introduce them to flock without the older ones being snotty. The 6 chicks that are a bit older seem fine with them. But the ducks were NOT happy! Had to separate them. A few more days hopefully they will be fine. Will have to put the 2 hens back so I don't have to do this twice with the same batch!!!