I have an Americauna that's been producing eggs with no shell and no membrane at all. She's been doing this for a couple of weeks, sometimes in the egg box and sometims it's like she just pooped only it was yolk and white! Prior to that her shells had been kind of thin for a while.. They get a good layer mix as well as oyster shell and diotomaceous earth with scratch, mealworms and veggies for treats. They're free range all day. My gold Wyandotte is laying regularly but the Barred Rock and the Austrolorp are molting. Otherwise she seems fine and looks good, acting totally normal. Any ideas?