I didn't know I could get a "bad" fresh egg, so I googled and found this, which others might also learn something from: http://www.wikihow.com/Tell-if-an-Egg-is-Bad Tip: The floating test works because the air pocket inside the egg gets bigger with time as the egg contents lose both moisture and carbon dioxide. As the air pocket gets bigger, the egg is more likely to float.
it works too, I got a bad egg the other day... a hen laid it, left it, and it wasn't in the boxes, so I didn't see it for who knows how long...
