Hello everyone. Need some advice on vent sexing. I've got several mixes here on the farm, one is 9 wks, the others are 7 wks. Is it too late to vent sex them? One of the 7 wk olds has a distinctive duck quack, the others are really quiet but I would like to be sure because I can keep them as egg producers if they are ducks. I picked up one today and I couldn't even locate the vent! So I need help. Oh yes, since these are mixes, (Pekins, Rouens, Khaki Campbells) Im thinking that i wont be able to wait and rely on the green heads. Many thanks everyone.