Occasionally, a hen will lay an egg inside of an egg, a phenomenon called counter-peristalsis contraction, and it occurs while the hen is forming an egg in her oviduct.
It’s getting easier for people outside the backyard poultry community to understand why so many of us choose to dedicate a portion of our lives to raising and caring for backyard chickens. I don’t get the same reaction I used to from suburbanites when they find out I raise backyard chickens through casual conversation.