Feather Plucking

[skyefry]

Hi everyone! I am currently dealing with a feather plucking issue and would LOVE some new ideas. I had the culprit separated for 3 days previously and when reintroduced everything seemed to be fine. However today I noticed the one hen she is bothering is becoming more bald again. They have a protein rich feather fixer feed, flock blocks, ample treats, space to graze and even toys. What am I doing wrong? Is there something else I can try? They have lived together forever and this issue just started. They are 2yrs old. I also don’t know when this is happening as I’ve never actually seen her pluck her feathers. Possibly at night?

 

[nuthatched]

Cut out the flock blocks and treats. Is it 17 or 18% feather fixer?
Have you ruled out mites/lice?