Oh boy! Do I ever feel your pain! I also have a petite EE (Flo) who is a determined feather picker/eater. Such a chicken is also known as a cannibal. I thought I was catching the problem early when she was beginning to lay, feeding her daily rations of canned tuna, thinking she had a protein deficiency.
But the problem persisted and even started getting worse. Much worse. She went from one victim to shaving the feathers off four victims. I was at the point of desperation. I decided to try pinless peepers. So I ordered some (blue, not red) and when they arrived, I installed them on Flo. The problem didn't stop immediately. Flo still would pick feathers if her victim planted herself right under Flo's beak.
So I sewed saddles for all the victims and installed them. Gradually, the problem stopped. I gave it about three months and decided it was time to remove the saddles from the victims and the peepers from Flo. The feathers had all mostly grown back, and Flo seemed to be cured. However, in three days, Flo was back to her bad habits.
Sometimes, a chicken's brain will simply be wired wrong. It's not due to any organic problem that some are persistent feather pickers. I believe Flo is such a chicken. It broke my heart, but I put peepers back on her, and the feather picking has ceased. Flo has adjusted to the peepers. They were very sore and tender at first. And she has trouble navigating the plastic flaps on the pop holes. She has adjusted to that also. She waits to lay her egg until I come out to the pen to make one of my frequent checks. She stands in front of the pop hole, looks up at me, and "requests" that I lift the flap so she can go in to lay her egg.
She's very intelligent. She was also a very precocious chick. I'm more convinced than ever that it's all in how her brain is wired, and she's just going to have to wear peepers to control her deviant behavior. She's much too precious to cull.
