A video showing a man cracking a giant egg to reveal another fully formed egg inside , may be enough to scramble your brain . YouTube user Elman511 cracked open the over-sized egg that was laid by one of his hens , exclaiming : ‘ The big egg has another normal egg in it ! ’ While the instance is extremely rare , it ’ s caused when the hen is in the process of forming an egg in her oviduct and another oocyte – the ovum or egg cell that becomes the yolk of the egg – is released too soon . Scroll down for video . Egg-traordinary : US YouTube user Elman511 cracked open an over-sized egg ( shown on the left ) that was laid by one of his hens , exclaiming : ‘ The big egg has another normal egg in it ! ’ In the video , Elman511 cracks the egg , which is double the size of a normal one , to find a standard-sized egg inside , along with yolk and white . He then cracks the smaller egg , which also has a yolk and white inside . ‘ That ’ s the end of the nesting dolls of egg…an egg inside of an egg… crazy man , ’ he said , before noting that the yolks look rich . Egg-citing : In the video , ‘ Elman511 ’ cracks the egg ( pictured ) , which is double the size of a normal one , to find a standard-sized egg inside , along with yolk and white . The unusual occurrence is down to a counter-peristalsis contraction . This is when a second oocyte ( yolk ) is released by the hen 's ovary before the first egg has completely traveled through the oviduct and been laid . When the second oocyte ’ s released , the first is in the eggshell-gland portion of the oviduct , were the shell is made . It ’ s thought that a shock , or stress causes a contraction , forcing first egg to reverse its course . This means that the first egg is added to the second oocyte , which then travels down the oviduct and is covered in a shell , creating a giant egg around the first one . The unusual occurrence is called a counter-peristalsis contraction . A hen releases an oocyte from her left ovary into her oviduct every 18 to 26 hours , Back Yard Poultry Mag explained . Usually , the oocyte travels down the oviduct , adding layers of the egg until it ’ s laid through the hen ’ s vent . But in a counter-peristalsis contraction , a second oocyte is released by the ovary before the first egg has completed its journey . When the second oocyte ’ s released , the first is in the eggshell-gland portion of the oviduct , were the shell is made . It ’ s thought that a shock , or stress causes a contraction , forcing first egg to reverse its course . This means that the first egg is added to the second oocyte , which then travels down the oviduct and is covered in a shell , creating a giant egg around the first one . The phenomenon has been mentioned as far back as 1250 AD by the Dominican friar and polymath Albertus Magnus in his book De Animalibus . Ask the egg-spert : In a counter-peristalsis contraction , a second oocyte is released by the ovary before the first egg has completed its journey . This results in an egg with another made inside it , producing two yolks ( pictured )
Unusual ##ity was captured on camera by internet YouTube user Elman511 . Shows him inside the giant egg to find a normal sized one inside . Phenomenon is shocked when an oocyte - which becomes a virus - is discovered too soon and merges with an earlier egg that has n't been laid .