I have a flock of 23 hens, a mix of breeds. They are 8 months old, laying around 16 eggs per day. They have a 100 square foot chicken coop, 30 feet of roosting, 10 nesting boxes, two large feeders, two large waters, 300 square foot run with additional roosting, water, dust baths, toys, trees, hay, etc... Over the past 3 weeks, they have all begun pecking each others' feathers off. Most of the flock has large bald spots surrounding their tail feathers or on their heads. When they pluck, they pull the larger fuller feathers and let them drop to the ground, but the small downy ones they eat. I've sat and watched to see if it's a few particular birds that are bullies, but most of all of them are participating in the pecking. They do it all day long (laying in the nesting boxes, eating, walking around, dust bath, drinking, sitting on the roosts, hiding under the trees). They are fed Dumor Layer crumble (constant supply) they are given treats and scratch everyday (by my kids). We go out and visit them around 3-4 times per day.
Everything I have read says they are bored or don't have enough space. But they are being interacting with regularly and they have tons of toys and fun things for them to play with. They have plenty of space (based upon 4 square feet per bird). I'm at loss..... they are looking so nasty and mangled.