what would cause my flock to pick on one hen?

[darkchick182]

i have recently purchased a younger hen to add to my small flock ( originally 3 hens and a cockerel) when i tried to intergrate her the cockerel first pecked her and then the other hens begain to do the same. i seperated the younger hen out and tried to gradually intergrate her when the flock are free-ranging and the flock still seems to attack her. what could be causing this???????? i have tried anti-pecking spray and even rubbing the flocks bedding on her.
really need advise as i dont know what to do any more?????

 

[sumi]

Your flock is re-establishing the pecking order and making sure the newcomer is at the bottom. Unless they injure her I'd suggest give it a bit more time and let them sort it out.