I posted last week asking about egg eaters because I brought in 2 new hens and the next day had 2 broken eggs, the day after 1 broken egg and 1 good one. I moved one of the hens out and isolated her to see if it would stop. The next day I got 3 good eggs (including the isolated hen egg). Next day I had 1 good egg and 1 that was cracked, but not open. After that all good eggs. I moved isolated hen back into the main coop (well it rained and she moved herself back in during the storm!) and the next 3 days I have had all good eggs... 2 to 3 per day from the 4 hens old enough to lay! So whatever it was that happened it is over... thankfully! Maybe just a run of weak shells?