I have taken a strong liken to all my ducks. I thought I sexed them correctly by bill color. The bill on 3 out of 4 of my Rouens turned bright at 3 weeks except one that's bill stayted black. So, they are five weeks on friday, and by 5 weeks the drakes bills turn a greenish olive color. Today when I was picking them up I saw that 3/4 of my ducks have a greensih bill. So I am left with.. 3 drakes and 1 hen, that I hope the sex-change fairy doesn't get a hold of. What should I do now?!