I have (had ) 18 ducks. As I got a new group I added a new house for them to sleep in, and they all sort themselves into the same houses each night at Ducky Round-Up, it's so fun to watch. The groups are: 2 Pekin hens 1 Khaki Campbell drake + 3 KC hens 1 KC drake + 2 KC hens 1 KC drake + 7 KC hens They hang out in their groups in the yard all day, but the KC drakes will chase & mate with hens from other groups. I know because you'll hear loud quacking & see 2 or 3 drakes chasing down one duck hen. But they leave the Pekins alone. The other night a raccoon killed one of the KC drakes, the one with the 3 "wives". I've been waiting to see if his hens will join up with another group. But they still seem to hang out in the same corner of the yard that they used to, and still go into their house alone each night. Is 2 drakes to 12 hens a good ratio for optimal fertility? For harmony? I notice that some of the hens are bare at the backs of their necks, maybe they're getting too much action. I have some new KC ducklings growing up, I could keep one of these new drakes if needed. Please let me know what you think, thank you!