I have 3 8 week old chicks and just picked up 2 6 week olds. I let them run around the yard for a while initially and the most dominant 8 week-old chased and pecked at them a bit. I put them in the coop run to "sort things out" and the older chicks are still pecking at the younger ones and chasing them away from the food. Any advice? As a side-bar, I already have separated my 4 year old adult hen from the 8 week-old chicks as she had previously pecked one of the other chicks to death.