you get those from time to time, usually when they first start laying until they're about a year old. I know they go by a few different names, but I call them fairy eggs. They usually contain some egg white and bits of yolk, or even no yolk at all. I like to feed them back to my chickens or save them. If I'm baking and cut the recipe in half I use a fairy egg when the original recipe calls for 1 egg.