There are a lot of variables that determine whether or not people leave their roosters with their hens. Right now I have an adult roo, a 3-month old and at least two 1-month old cockerels. They're all together with the rest of the flock, but as soon as the young ones get to breeding age, they will be separated and placed in a grow-out or bachelor pen. I don't have enough hens to make it feasible for them to all stay together. A couple of years ago, I had 50 straight run chicks. At least half of them were male - they also got separated from the hens when they got to that age. I will, however, keep my mature roo with the hens.