Hi,
Its quite daunting this chicken keeping! I guess you must be new to it, rather like myself. Despite reading everything going, and actively searching for info on-line, and having my poultry lady on hand for advice, WE have still worried ourselves over the slightest thing, just like a first time mum with a new baby!
I havn't got to your stage, (yet, only week 5), BUT as Podstable said, there is probably a very simple reason for their behaviour i.e. mites of some description.
Surely yours can't be ALL be pecking each others feathers out, there must be a bigger picture. I reckon they need a good examination. Until last week, I hadn't mastered the once over, now I put my gloves on, whisk them up, turn them over, and part their feathers and fluff to take a good look at the vent area in no time at all. None of the girls complain and each are mite free (for now). That hasn't stopped me from buying every potion on the market, studying their poohs, worrying about their behaviour etc..... I reckon we care so much, which is why we are fretting. I even dream about red mite, it features in every conversation!
I also found quite a few feathers, (20), lying on the floor of the house this morning and am naturally concerned about this myself. We are keeping an eye on our youngest hen, who hasn't quite bonded with the other two yet, and can't explain why so many feathers were on the floor. Naturally we jumped to the conclusion that the other girls are picking on her, which is the case on occasion. So goodness knows what goes on in the house of an evening.......
Clearly I am in no position to offer poultry advice, and experienced keepers will no doubt offer their support, but what I do know is, they are so rewarding, and worth every frayed nerve. The learning curve is admittedly very steep.......
I hope you feel a little reassured, and it would be good to know how you get on with hens etc.....
All the best, Sharron