I have 18 hens. I feed laying mash, they free range on 13 acres and i provide oyster shell all the time. My eggs are so hard and thick that my friends say they never saw such hard shells as my eggs. But one of the hens is laying a brittle thin shelled egg. so thin that most days its crushed by either its hens or another who gets in the nest to lay. Im familiar with the thin shells with new layers.. and an occasional one. but this is daily.. the pointed end will be totally elastic like and the rest of the egg will be very thin but it does retain its shape. i can push on the pointy end and push it down into the egg and it will harden that way. but mostly they are crushed totally. I dont know how i would be able to stand by the nest and figure out who is doing this. any suggestions? My chickens are so very healthy and i get a dozen eggs a day and no complaints from anyone in the penn. what would you do?