We have two year old Australorps that we bought in the Fall and are attempting to introduce two new girls, a buff orpington pullet and an 8 month old barred rock. We kept the new girls in quarantine for a week and then put them in with our australorps. They slept through the night with no issues, but when we checked on them in the morning, the australorps were clearly pecking and harassing the pullet. Should we keep her separate from all of them until she is a little bigger, or should they just work it out?