In 7 years I've never seen fly strike until now. My hen, Henrietta has been doing a squatting walk for 2 days. I picked her up and she had this huge mound of gunk and blood with maggots or worms infesting it. She is bone thin as well. I threw some Sevin powder on her butt and came in here to find out what to do. I guess I'll have to soak the butt and cut off all the feathers and what not that I can. What do I do after that? Debride it? I'm worried about how deep it's going to be. Can anyone offer me advice on how I need to go about treating this?