My son had an old-time chicken farmer tell him that the way to tell if a young chicken was a hen or a roo was to hold them upside down by their feet. If the chicken just hangs upside down with out much of a fight it is a hen. If it is a roo it will try to free itself and try to raise it's head and body. I tried it with my 1 1/2 week old babies and it seemed to work. I have straight run chicks and what are supposed to be hens. The "hens" just hung there when I tried it with them. Some of the straight run definitely tried to free themselves. Has anyone else heard of such a thing? Will you try it and let me know if it works for you? It seemed to for my babies.