This morning I found a duck egg from one of my 2 year old rouen ducks right next to the water pool. They always lay in their box so it's placement alone was bizarre to us. The egg has a plastic bag looking skin around it. I pulled some off to investigate but since I've never seen this before, I left it as is for the most part. Does any one know what this is or why it happened? All my duck eggs are presumed fertile.