I have 3 Polish chicks I think approximately one month old. They are not yet fully feathered, but two appear to have little bumps forming on their head at the front of their crests. I think it's the start of combs. At what age do they usually start developing? Do they develop earlier on Roos or is it about the same time regardless of sex? My hubby is convinced at least one of them is a Roo. I will try to take pictures when I get home.