I had two gold laced hens that I loved to look at. They would run around and steal feathers off of other hens backs to the point of making them scream, bald backs, vents, and bloody vents.
They even did it to each other (but not to themselves). It was like they couldn't help it-walking along, looking for food, and then suddenly "FEATHERS!!! NOM!!!". We tried everything from a higher protein diet to even MORE space, but in the end I gave up and I got rid of them to someone who fell for their looks with a full disclosure. I'm tempted to try anther strain, but it will probably wind up the same way so I'm sticking to what I've got left and avoid the mess.
