I have three large hens and a rooster, all from the same hatch, that are now almost 24 weeks old. The hens have not begun to lay yet. The rooster has never attempted to mount one of the three large hens for mating. Yet, anytime he could get close to the little silkie hen with a chick, he'd viciously mount and try to mate with her; maybe he actually did. Is it possible that he's afraid of the large hens? BTW, I have the silkie and her chick back in their own coop now, and they have a fenced-off section of the run to themselves.