I am on my second batch of chicks so this is the first time I've had to worry about introducing new girls into the established flock. Right now the babies (one week old) are in a secured brooder box in the coop with the big girls (2 yr olds). They can hear each other but not see. I am just trying to figure out when they will be old enough to join the rest of the flock unsupervised in the yard? Also logistics on feed can the older girls eat the chick starter and be fine or do I need to find a way to sepate the feed until the littles ones are ready for lay crumbles?