I got 8 "straight run" chicks about 10 weeks ago--all BO. I was hoping for 6/2 but it may be 5/3 or 4/4 or even 3/5. At any rate, at what age will the roosters crow? A few are larger, with bigger feet and combs, and they are belly-bucking some. I figure if they are crowing, they are male, but it will be a while before I see any eggs. So what do you think? When will I know "for sure?"