Today, I was hanging out with my 14 week old girlies while they were in the chicken wire pen (There is no grass in the run and they are only in it under supervision, otherwise they are in the run). Gidget, my barred rock, was standing with her butt facing the other girls, and she pooped. All four of then (buff orpingtons) came over and started pecking Gidgets' vent. I shooed them away and picked Gidget up. I looked at her vent for blood or damage. There was none. I put her down, and they started doing it again. I stomped my foot and they scattered. I am in my kitchen now and can see the coop from the window, and they are leaving it alone. I have never noticed this before. What can I do to prevent it?