Chicken bullying

[15hjschi]

I am a first-time chicken owner and have a flock of five 5mo old hens that I got all at the same time as chicks this spring. They are all laying except one, who is also slightly smaller than the others. She has been getting severely picked on by her flock mates (mostly by one hen, but sometimes the others will join in). They pulled out a lot of the feathers on her back, legs, and around vent. I put a fabric saddle on her which seemed to help with the back plucking for a few weeks, but the problem is persisting. I wonder if they know she is slightly "behind" them developmentally. Will they stop eventually? Do I just let it run its course and hope they stop when she starts laying? Do I put pinless peepers on the main offender? Any advice welcome!

 

[sourland]

How much space do they have? My initial inclination would be to put Pin Less Peepers on the primary pecker/plucker.