I have 9 call-ducks of 4 drakes and 5 hens that are housed with 4 Muscovy hens in a 10 by 20 feet pen. I have never had any trouble with the flock fighting or anything, mostly once in awhile the Muscovy would softly push away one of the calls or each others, if they are all going for the same food just like any other ducks would do. They all are very nice ducks and they love people. I let them out to free ranges alot in the summer and they have a nice lake to go to in my backyard lol I have spoiled ducks, I don't even clips their wings. I notice my ducks will fly over the lake every time they are set out and they always come back and land on the lake in front of my back door. Now what my question is, if I introduce a Drake Muscovy to the flock, will there be trouble? I really want to breed my Muscovys and I would love to see the girls walking around the yard with their offspring. My ducks are my loving hobby and I think it'll be nice to sell ducklings in the spring to anybody, not for the money but for the fun of having them. All my Muscovy hens are a different color, One is black Laced, one is Chocolate Ripple, one is all white with a black grown and The oldest one is a pied of blue, brown and white.