So I bought 5 chicks (a week or so old) from a local farmer who wanted "rid of all these roosters".....he had about 150 chicks and had carefully sexed them all with his Chinese Sexing Crystal. He said he had been "doing this for years and was right 98% of the time". He only wanted .25 each for feed offset since they were, after all, useless roosters. Now granted, they are yard birds to the extreme. Some have feathered feet, some have 5 toes but no hair, some have silky hair on their head without five toes, one even has EE muffs. Anyway, they are now 10 weeks or more old. 2 of them? Roosters, no question. the other 3?? HENS. Rounded saddle feathers, tiny pink or no comb to speak of, body shaping out rounder, the whole nine yards. Sooooo, y'all can keep your crystals IMHO. I will wait until they crow or lay an egg as the saying goes. At some point nature makes it pretty clear.