I have a flock of six cayuga ducks. However, I was always planning on only keeping four, maybe three depending on the sexes. They are just shy of ten weeks old and four have distinctive quacks and two cant quack for the life of them. Is it safe to say I have four girls and two boys? I am ready to sell the extra but want to make sure I am keeping the sexes I want and would hate if I rushed it. Also, if it is too early, when can I expect to know without a question? Thanks!