Hole in chicken’s back

[BirdLover2005]

Does anyone know anything? Where this came from? What it is? How to fix it? We just found it on her today but her butt has been bare for a while now and she is usually the one picked on by the male guineafowl.

 

[Cecisflock]

picked on to the point of a hole maybe?

 

[BirdLover2005]

picked on to the point of a hole maybe?

Maybe but the hole looks deep. Can’t see the end of it. Could it be like a worm hole or something?