During the summer I had 4 Buff roosters, and at least some of them were frequently breeding with the hens. In the fall I got rid of 3 and kept my favorite. He tries now and then, and every so often succeeds, but I don't think the eggs are fertile - at least, I know some of them aren't. I have 12 hens. Is it the time of year, or should I try to find another rooster?