I have 5 hens laying normal eggs with thick sheets as of 2 weeks ago..however I thought 2 just weren't laying yet but when I was out side I turned around and say what was an egg with an skin thin shell.. and the chickens ate it before I could blink then there was another one same thing. I had already collected 5 eggs that morning ..this happened in the evening almost sun down..so.2 questions 1.why is the shell so thin when I give them oyster shells and the other 5 don't have soft shells....2. why they both laid outside the coop and at an unusual hour.