Our 6 month old Chickens still are pecking a gang up on our 3 month old chickens! They have been in the coop together now for over a month. The 3 month old ones are fenced off inside with chicken wire to keep them separate from the older ones but to where they can still interact and see each other, but every time we try to let them out to be together the older ones kind of attack and gang up on and peck the little ones still! How long is this going to last?!