It's supposed to keep the chickens from pecking at an injured hen/rooster. I bought some today. My rooster pulled some feathers loose and when she bled a bit all the other hens started pecking at her. (Although this is mostly conjecture. I didn't see him on her, but I did see all then hens pecking at her, and she did lay an egg later) I'm letting my hen heal up for a week or so and then will put her back with the other ones. When I do I want to put this on her to keep them from hurting her again.