My 21 week mallard drake attacks my 11 week runner/kc mixes every time they are around each other. One minute he seems fine and the next he is mean. They are cooped separately and I frequently let them forage together with supervision. I need to get them to get along because I am rehoming my drakes soon and can't until they get along. Help please! This is a nightmare. I have a buff girl that is 21 weeks and my younger ones are 2 boys and a girl 11 weeks old. The youngers are bigger than my mallard but he doesn't seem to care. He also attacks my 11 week old chicken (just discovered is a roo) my 21 week barred rock hens attack the roo too. I feel like I need 3 coops to keep everyone happy! Right now I have 2 coops with all 21 weekers in one and all 11 weekers in the other. Problem is that they are mixed flocks chickens and ducks in each coop. Ugh. Please I need advice!