I have no idea why this little pullet started staying in the coop while all the others free-range. She used to go out with them but the last week or so every time I go up there she is inside by herself. I haven't seen her being picked on, but maybe she has been? She runs around looking for food, gets drinks, climbs up and down the roost...looks healthy to me. I haven't tried to catch her and have a closer look since she seems lively. Any ideas?