I had the same problem recently. I found that placing a golf ball in the nest helped. Also, the chickens main problem is they weren't being turned loose enough. We have been letting them free range, but after loosing two to a hawk (one being our best layer), no more free-ranging. So, they were put up for a few days while we built a small make-shift chicken run. Then, I caught them in the act. One had a piece of shell in it's beck, the other was eating the white. We hurried and got the chicken run built, and we get 2-3 eggs a day again. Maybe this info will help. Good luck.