I have about 25 hens - 12 are between ages 2-3 and 13 are 9 months old. We culled our rooster 2 years ago because it was too aggressive to my wife and I, and the hens have been without a rooster for all that time. The dominant hens peck the news hens pretty badly at times, and I want to add a rooster back to the flock to add balance. What are the considerations I should have for adding a mature rooster to the flock? Beside trying to find a mellow one who won't attack my wife or I when we go into the chicken yard?