I remember reading about this experience before but can't find the post... I have only 4 hens; the Australorp has been laying every=other=day for the past five weeks. Yesterday I had 3 lovely eggs in the nest boxes and was so proud! Today I find a single, egg with NO shell. Looked just like I had cracked one open in the nest, with yolk broken. Since all eggs were perfect yesterday, could this be from the last not-quite-ready girl or can they make a shell one day and not on another? And what do I do to help fix this = it was a bit shocking/creeepy to discover.