Chinese Chicken Lays Huge Egg With Another Egg Inside It

A chicken in China's Guizhou province laid a huge egg. Inside this large egg there was another egg. The 87-year-old owner of the chicken says she thought the hen was dying it was trying to lay the big egg. Take a look:

Douglas Russell, bird group curator, Natural History Museum explains the rare egg within an egg phenomenon in the this video from New Scientist. Russell says a developing egg gets pushed back up the oviduct by a series of abnormal contractions. The egg then gets surrounded by another egg. Take a look:

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