Newbie here. Just picked up 12 Barred Rock pullets from local feed & seed today. Got home to put in the brooder and see that 2 have missing "butt" feathers. One has just a small spot but the other basically has no feather/fuzz at all. Do they have something wrong with them? Should I isolate them from the others? Could this be a result of being in "close quarters" with too many others and a result of feather pulling? What should I do? HELP PLEASE! I am very concerned. Thank You!