I could really use some advice on chickens that aren't getting along. We had 12 pullets that we raised from chicks and we bought 3 barred rocks 5.5 weeks ago, about the same age as our flock. We kept them segregated for about a week and a half, and then set their pen up next to the others for about 1.5 weeks. We let them out to free range a couple times at the same time with minimal issues, though they mostly stayed away from one another. About two weeks ago we built a new coop and put all the chickens in it at night together. There has been fighting ever since, day and night. Now the barred rocks jump out of the run every chance they get because the others chickens won't let them eat from the food container. I thought by now they'd have figured this new pecking order out but it is clearly not improving. Any advice?