My chicks are 3 weeks old tomorrow. I ordered 12 pullets from MPC in a variety of brown egg layers (and one EE). I've been trying to tell if I have any roos. I have read posts talking about leg size and color, and overall size. I have noticed that some of them have already started to get their combs. Does early comb development have any indication of sex? I'm really hoping I don't have any roos, but I do understand that sexing is not 100%. Is 3 weeks still too early to determine if any are roos?