The one on the right is an Ameraucana egg, slightly blue/green and normal sized. The one on the left is called a "Ghost Egg" or sometimes called "Chicken Fart" When a hen starts laying for the first time, or after she's been thru a moult and "recovering" it seems like they need to "remember" how to lay, kinda clearing the pipes and these mini eggs are the results. My grandson K. saved this one for me, he knew grandma had to have a least one "Ghost" in the cabinet. Now I do.
Thanks guy
