We got a 3 month-ish old black star (sex link) to put in our newly completed coop, we have been raising some ameraucanas and a polish from a few days old. The ameraucanas are about 4 weeks now and the polish 5-6. The young ones all get along well. We wanted to introduce them together (and get the young ones outside since they are a bit big and smelly for inside) so I put netting up to shut off 1/3rd of the coop from the rest and put them out there where they could see each other and interact through the net. They've been like that for a week or so. I wanted them to get a little more interaction and have the little ones have access to the run (which is on the other side), so I built a little door in the netting the little ones could get through but not the big one (so they could retreat to their side). We already tried introducing them a little in the past and she has been pretty aggressive. Well we let them use the door and stayed around to see how things were and she was being very aggressive, grabbing hold of their wings and pecking even while they were retreating and peeping, not getting in her way or starring at her or anything. It wasn't that bad if we knew she was going to stop after pecking each of them, but then she cornered the polish (who had her back to her the whole time) pecked her on the head real hard, grabbed hold of her and tried to jump on top of her like she was going to pin her and do as much damage as she could. The poor polish ended up bleeding on her head. She was just in the corner minding her own business. I was/am furious with the black star. Now I swapped their sides and she gets the 1/3 and they get the 2/3 and run. (she barely used the run and they do) I always thought they just pecked each other until one retreated or showed submission, and could get bloody if they were both strong willed, but shes pecking them even while they are running away and not challenging her, or just sitting there minding their own business. Is there any way to introduce them where this wont happen, right now I'm just going to leave it like it is until they are much older, she can live on the small side for all I care, but I feel like even then shes going to be super B*&chy and attack them.