It took me 2 weeks to cure one of my young hens of this. She picked a full circle of skin bare to warm eggs and she began laying on the ones laid by the others and tossing feathers over herself. I started going to the barn earlier and getting the eggs out, and eventually she stopped and calmed down. it was like she was the ' most demure of all' and had a little secret. Fortunately she was gentle with me though she was testy with the others, even my alpha girl. She's fine now, feathers are beginning to regrow. As a precaution I treated her with food-grade DE and Dri-Kill, but she never showed any signs of pests, and the whole coop is 'closed flock' and treated with DE.