I've cooked stuff millions of times using eggs and have never had an egg with two yolks in it.� So I was quite excited this evening when I was making an omelette for Sam and cracked open an egg� (because� you can't make one without doing) and there were two yolks inside.� Hooray, I thought, I've found an egg with two yolks in for the first time ever!� I rushed out to show Claire and she was suitably impressed.� This was exciting!� I've never had an egg with two yolks, and suddenly here one is!� Right here!� Now!
Well, this was going to be a two-egg omelette so after the excitement wore off I took another egg and broke it and guess what?� Yes!� It had two yolks in it too!� So having never had an egg with two yolks in it before I've suddenly opened up two in succession and they both have two yolks!� Wow!
Here is a picture of my two eggs:

Do they get put in the same box on purpose?
you can specifically buy double yolkers in Sainsburys.
I think they tend to crop up in pairs or more - something to do with the same hen lying the eggs