I got a pullet from my friend as she could not cope with her being a bully to her original flock. I quarantined her for a month and today i let her out to freerange with my flock of 2 hens, 2 pullets and a 16 week cockerel. Well it went very badly, my 2 older hens attacked her straight away and kept attacking every time they went near her, then the cockerel (who is normally very sweet) attacked her aswel, his hackles went straight up and he kept jumping up and attacking her till i seperated them. I'm really worried now as i was getting ready to introduce some 15 week old chicks to my flock , now it scares me to do so. What can i do to make this easier on all of them?