I just mentioned molt because I thought you did. :hmm
Your girls are reaching maturity and with that come an increased desire for more room. Feather picking often starts out as one bird trying to move one but can quickly escalate into a behavior done just because they can. The vent is a common...
Your girls are too young to molt. That will happen next year in the fall. Your birds sound crowded. Your coop is too small and things are gonna get worse as winter settles in. It also sounds like picking has become a habit in some of your birds. Chickens need to run, scratch and peck all day to...