what causes comb and wattles growth in young chicks? i have two roosters who both showed sign of their sex at around 3 weeks. but now at 6 weeks, one's comb and wattles look amazing and the others is much smaller. the smaller one is more loving to me, and more social with the other chicks. the bigger one is harder to catch, and stays on the fringe of activity. is it just hormones or more complicated like genetics? I'll try for pictures later, the big boy is hard to catch. both were from the same hatch. from a private party, not from a hatchery.