Mine had the black dot also, the one w/ the ticking had a bigger dot, the more buff had a very small one. Our only hen has a ticking problem. We are hoping to breed it out. This is a 4h project for my son. There is no doubt that these birds are nankin I guess I will post pics of the adults. We are working with what we have, and what we have are two great roosters and a hen with a ticking problem. Also, it prob. Doesn't mean anything but the buff is a strait comb and the other is a rose.