I was out feeding yesterday and noticed one hen with her feathers raised about mid spine. After catching her up, I further inspected her. I found a large lump on her back (about mid spine) raised 3/4 of inch with a diameter of a half dollar. Also on top of this lump is something hard and black, I first assumed this was clotting from maybe the skin breaking open. It doesn't appear to hinder her or hurt to the touch. I've looked in my books on chickens and this doesn't look the same as the mite problems i've seen pictured. Should I be looking and treating for mites or is this a tumor. I know you will want a picture, but I don't have a camera. Thanks for the help in advance.