Keep us posted as to what they turn out to be. Metzer got my two Mallard ducklings a few years back right when I ordered two females but anyone can make a mistake when sexing them that young. I was just going by the shape of their heads. My Call duck that I think is a boy has a flatter head and the one I am calling a girl has a more rounded one on top. The rear end of my possible girl is pointed too and the one I think is a drake has a blunt rear end. I could be wrong but so far I have almost always been able to sex them. One time because of the whistle I thought I had one of each and it turned out to be two hens. One of these are whistling too which usually means a boy but could also be a girl.They were sexed by Metzer farms as female, I just keep getting paranoid one is a male because her personality is so obnoxious lol