I have 3 6-week-old ducks. I'm wondering of you can help me figure out their sex. I think i have 2 drakes and 1 hen. The 'drakes' have a green sheen on their heads, and their bills have a blue tinge. They also chirp and squeak constantly, but I've never heard them quack. The 'hen' has a mottled tan head, 'her' bill is more yellow, and 'she' quacks all the time. What do you guys think?