So, after weeks of me whining and complaining about no eggs, then one egg, then two ,etc. All six of my big girls are finally laying. But, Saturday and Sunday both there was a very thin shelled egg that was cracked open (Probably stepped on, they were in the nest with other eggs). I know this can happen w/ new layers, but at what point should I be concerned? I am not sure which girl it is doing it, of even if it was two different ones. I feed free choice Purina Layer feed w/ Omega III, and a few treats of veggies, bread, sometimes cheese or meat but not often, and mealworms on occasion, and whatever bugs are in thier run. They are 21 weeks old.