My little BO has a bump on her back close to her butt. I noticed it about a week ago because she opens up her feathers around the area and nibbles at it. I'm guessing the bump must be an irritant since she has pecking at it for at least a week now. It looks a lot like a really really big pimple- although it doesn't feel like one. It is tough, solid and protrudes about a centimeter. I wish the picture was clearer but she was squiming. It does not look like a tick bite. Any advise on what it is would be most appreciated.