What are the chances of finding half a dozen double yolk eggs in a single egg box purchased from a store. The BBC is reporting that two friends were cooking and in the process were cracking eggs in a mixing bowl and the first four eggs they cracked were all double yolkers. According to some Brit egg info service only one in every thousand eggs on average is a double yolker. Then the likelihood of finding four in a row is one in one trillion...12 zeroes. The article then went on to discuss how double yolkers are made and that most of them are made by young hens, 20 to 28 weeks old.