What causes this bullying?
QI have three hens that have lived happily together for over 18 months. Two of them have now started attacking and pecking the other one. They will not allow her to go to roost at night so she sleeps outside, and I have temporarily separated them. Do you have any idea what may have caused this and if I can stop it?
AAnne Perdeaux says: There are several possible answers to this question, and finding the reason for your hens’ behaviour is likely to be a process of elimination. Feather-pecking and bullying are often due to stress. Causes of stress can include shortage of space, nutritional deficiency, lack of water, changes in routine, a disturbance, or poor basic husbandry. Chickens also become very stressed if they are too hot, so as this problem seems to have started during the summer months, make sure they have access to shade and their coop isn’t getting over-heated. If you are able to let them free-range, this often helps to restore harmony.
Another possibility is ill-health in the bullied hen (apart from any injuries she may have sustained). Chickens protect their flock by driving away sick birds, and it’s possible the two aggressors have noticed something you haven’t. Give her a good check-over, especially for external parasites, and worm all the flock too.
Hope this will help you to find a solution!