This spring I got three Naked Neck chicks. As they have been growing I have had the toughest time telling their sex. It seems to me that hens of this breed have fairly decent size combs and waddles. Burt the first photo is the only one I am sure of, he has been crowing for well over two months, but the other two have not. The red one looks like he will try, but never does and is the smallest in size. All three have thick legs and the solid black one is definitely the largest in size, but not crowing. They are 17 weeks old. Can anyone tell me if these are definitely roosters and why only one crows?