This morning I head out to the coop and to my delight there are four eggs waiting for me. I am all the more impressed considering the sub zero temps. Sadly, one of the eggs had frozen and cracked. I brought all four eggs in the house. The three good ones went in the fridge and the fourth cracked one I left on the counter. The crack extended about 180+ degrees around the midsection of the egg and was about 3-4mm wide, with some frozen egg white protruding. When I came home for lunch, the crack had not only closed, but it was barely even visible. I wiped off the egg and it appears fine, but for the now hairline fracture. Freaked me out!