I am new to the chicken world. I have 5 Buff Orpingtons. 4 hens and one rooster who until the last couple of days has been very sweet and docile. They are 20 weeks old and just recently when we open the coop up in the mornings he immediately jumps out and shows aggressive behavior. He pecks at our pant legs and yesterday he bit my hand. I desperately want to keep him. He is a beautiful bird, but I have 2 children and I don't want them to be afraid to be in their own back yard. He doesn't attack or chase anyone at this point, but I want to nip it in the bud before that happens. Any advice?