So we got 2 black austrolorp chicks when they were about 3 weeks old and we were told that they were only a couple days apart in age but there was a distinct size difference. They are now about 12 weeks old and the size difference and rate of maturity has been very different. We are wondering if one is a roo and the other is just a runt. Any guesses? We also noticed that the one we suspect is a roo has lighter colored eyes than the small one and our other black austrolorp hen. Is there any significance to that or does eye color just vary? Thanks for any feedback. We live in a city so we can't keep a roo. We are hopeful (but not too optimistic) that we are wrong about the big one.