I used to get the occasional broken egg.....nothing left but a small pile of white. (they get oyster shell free choice) Now I am getting an egg with a hole in the end and all of the inside is gone. Last week there were 3 in one day. I have 28 chickens. I took the three and filled them with frenchs yellow mustard and put them in the boxes before bedtime. When I went down to let them out in the morning, they were licking up that mustard like it was the best treat ever. Backfired!!!! Is there something else to try? I can't wait in there all day to see who it is. Thanks