I have 6 RIR pullets, the runt gets picked on by the larger hens -- OK to be expected. But lately one (or more) has a habit of jumping on the runt's back and pulling on the comb, and her back feathers are getting damaged from the footholds. They have a decent sized coop (100sf), a decent run (300sf) that they have daily access 9AM-5PM, plenty food water, multiple options. Getting 5+ perfect eggs/day. Any advice on how to prevent the situation from getting worse? It is not being pecked, just the damage from the footholds on the back.