Here is the video. I've seen many a double yolked egg (even a triple), but never 2 yolks with an entire egg along with it. https://www.facebook.com/video.php?v=10208361868942224 My questions are this: 1. What causes the double yolk? (with or without the whole egg inside..) 2. A story here http://www.dailymail.co.uk/sciencet...n-cracking-open-giant-chicken-egg-INSIDE.html says that the second egg is from a "counter-peristalsis contraction." Is this harmful for the hen?