I recently bought 10 Black Star "hens" that were supposed to start laying in about a month or so I was told. I am fairly new to raising chickens, but I'm pretty sure that 5-6 of these "hens" are really roosters. I read that Black Star roosters would be black with white and hens are black with brown. While most of mine are black with brown a lot of them look like roosters. They are very tall and have thicker legs then my other hens, and I have yet to catch one in the laying boxes. I know for a fact that one is a rooster because I saw him mating one of my other hens. Is there a way to tell for sure if they are roosters?