I can't believe I did this but the chicks needed to be out of the house. My Light Brahmas 3 1/2 weeks stayed in the coop with the 9 1/2 week Bard Rocks and 7 1/2 week Buff Orps, and they survived. I watched them throughout the day seeing how they were treated by the others but they would just peck the head but not causing blood or chasing them. The little guys would just run and gather with each other. I would be there and try to show to leave the Light Brahmas alone. It looks like the big ones just kept the food area to themselves because this morning I went out to let out the chickens and the babies were all over the food. One good thing is that the big chickens have their place when the sun goes down and sleep until morning. The little ones are not used to that yet. I'm so glad they can get along, well, they aren't all huggy snuggly but they can stay together.