I have 10 barred rocks 3 weeks of age. The hens that laid the fertile eggs are purebred barred rocks. The rooster is a barred rock, and what looks to be RIR mix. He has the bars of a barred rock, but some feathers are brownish red. Maybe he has no RIR at all, IDK. Anyways, they had these 10 chicks. 4 of the chicks have the bars that look like a barred rock should. The other 6 are mostly black, no bars. The ones with the bars are developing a comb already, the other 6 aren't. Could it be that the all black ones are pullets, and the ones with the bars are cockerels?