normal feather pulling in coop, yes, no, maybe

[gingerpeach22]

The blond EE walks up and jerks out someone's feather, then goes to three or four others and does the same. Somebody lies down in shavings and another bumbles close by, reaches over for a peck and a pull. This is different from the status display of rush, stand tall, peck, and establish dominance. Should I cull Blondie? Others pull feathers, but she's the one I've observed several times. Will another take over her habit? Advice invited. Squirt gun with water? Trainable? They are about 4 months old. No roosters yet identified.
1) they have enough protein
2) bored because run not yet finished?
3) they get greens, visits from me, pecking ball with cabbage, carrots, apples

 

[Dora'smom]

My original flock have pecked on each other from the start. We have done the blu-kote for injuries, Pick-no-more, the squirt gun, etc. The only thing that worked consistently for us was the pinless peepers. The birds don't like them initially, but get used to them fast enough. It prevents the birds from picking feathers, but they can still eat and drink, etc. It's worth a try to break a bad habit like this. You can get them through several online sources. Good luck with your pickers.