My 4 chicks are 6 weeks old now and really developing into grownups. But one of them in particular looks a bit like a roo to me. She's my speckled Sussex, Mildred (or Millard, if she turns out to be a rooster). Photo below of her when she was 5 weeks old. Not a perfect shot, but she wouldn't hold still. My other 3 are Wyandottes, and they have fatter butts than Mildred does. Also Mildred's tail feathers seem to stand up more. Any educated guesses on gender are most appreciated!