One of our hens is getting her feathers plucked out, on her back, near her tail. SHe's also been "nesting" and laying down (not sick or hurt though) We do have a rooster (who was supposed to be a hen) that is maturing. Is it most likely him? I watch them and don't see any of it happening. Should I get rid of the rooster, or is this normal behavior? (They were born in March) Thanks!