Find the trigger before you treat the behaviour
Feather pecking almost always has a starting reason, and punishing the pecking without finding it just moves the problem. Run the usual suspects in order. Space: birds who cannot get out of each other's sight lines all day peck from sheer friction. Boredom: a bare run with nothing to work at turns foraging energy onto flockmates, especially in winter when hens are housed for long stretches. Parasites: check a few birds around the vent and under the wings for lice and mites, and check the coop's cracks too, because an itchy, irritated bird pecks at herself and teaches the flock the habit. And timing matters — an outbreak that starts the week after a new bird, a new coop or a feed change is telling you where to look first.
Space and things to do
The physical fix is to give pecked birds somewhere to be that is not in front of a beak. Add perches at more than one height so a low-ranking hen can get up and away, a dust bath corner, and visual clutter — shrubs, pallets leaned as screens, anything that breaks sight lines across the run. Then redirect the foraging drive onto legitimate work: a cabbage or leafy greens hung at head height so the flock has to reach and tear, grain scattered through deep litter instead of served in a trough, a turf or a pumpkin to dismantle. Hens who spend the day dismantling vegetables have noticeably less appetite for dismantling each other. If the coop's light hours have crept long and bright, that alone can fuel restlessness; dimmer, shorter-seeming days settle many flocks.
Protect the victim properly
A bird with broken skin or a bleeding feather needs out the same day, because hens are drawn to red and a wound in the run becomes a flock focus within hours. House her within sight of the others if you can — a crate or penned corner of the run — so she heals without becoming a stranger who needs a full reintroduction later, and put her back at dusk once the skin is fully closed. If one bird is the relentless ringleader, the better move is often the opposite: remove the bully for a few days instead. She returns having lost her rank and her audience, and a surprising number of ringleaders retire quietly after one exile.
Watch the bottom of the order
Bullying concentrates where the flock's pressure concentrates: on the youngest, the smallest, the newcomer, the broody sitting hen who cannot leave the nest box, and any bird already under the weather. Lay on extra feeding and drinking stations out of sight of each other during any tense period, and handle flock checks at bird level — part the feathers at the base of the tail and around the vent on a few birds each week, because that is where the damage starts and where it hides. Deep wounds, a pecked bird who goes off her food, or pecking that keeps spreading despite more space and occupation are the point to bring in a poultry vet rather than another cabbage.
Small checks, caught early
Feather pecking escalates in stages — a ruffled tail here, a bare patch there, then blood — and every stage is cheaper to reverse than the one after it. That makes it a problem built for routine rather than vigilance: the same person, or the same rota, looking at the same handful of likely spots each day will spot a two-day-old bare patch that a weekly look would find as a wound. KinsLe's Care Teams turns that into a proper rota — daily checks with a name against them, and the healing hen's isolation care ticked off as it happens — so nothing depends on whoever happens to wander past the run.