I have 5 black sex link girls that I have had from chicks. Never a rooster (could that be the problem)? They have all have been together since chicks and about 3 yrs now. Two of them (Roxanne and Chloe) have turned into thugs. Those 2 and only those have singled out Charlotte and bully her to the point of pulling her neck feathers out, chasing her until they catch her and pecking her. I currently let Charlotte out into the yard during the day to keep separate. They don't bother her on the roost at dusk. I'm right before having the bully's for Sunday dinner but Roxanne lays large and more often than the others. Henrietta and Savannah just sit back and watch do they not realize they could be the next victim? I'm open to all suggestions, sharpening the hatchet this weekend. Charlotte's comb has been laying down with brown dots on it if that means anything.