I hatched 2 pullets and integrated them at about 13 weeks. Mine free range so I let them out in the morning and they spent a lot of time keeping aaway from teh others. There was pecking at feed times but nothing serious. Milly, the smallest got most of it and kept out of the way. They slept separately in the stable for about 3 weeks and then we moved them in with the others after dark a couple of nights and all was fine. I think it is easier if they free range as they are able to choose to be away from the others until they are settled. Now everyone is together in the field. Good luck!