Fairy eggs, also called "wind", "witch", "cock" or the fairly crass "fart" eggs, are merely a glitch in the laying process that is fairly common in backyard flocks. Smaller than regular eggs, usually rounder and containing no yolk, these eggs generally occur either very early in a hen's productive life before her hormones and reproductive cycle are fully formed and working properly - or sometimes very late in a hen's laying life as her hormone production is winding down. They can also be the result of stress or a disruption of routine.
An Egg by any Other Name
These miniature eggs have had several names through the ages. In the Middle Ages, they were called "cock" eggs and were believed to be laid by roosters, or "witch" eggs which were believed to be the work of the devil. In Scotland and other European countries, the eggs are referred to as "wind" eggs. More recently in the US, they have been tagged with the moniker "fart" eggs. But I far prefer the Victorian title of "fairy" eggs.
Fairy eggs can be the size of a grape or marble, but are often as large as a ping pong ball, and are usually a bit more rounded than a normal egg. Often they are darker and more vibrant in color than subsequent eggs laid by that hen because there's so much less eggshell surface area that needs to be covered by the pigment particular to that specific breed, and sometimes the smaller eggs get an extra dose of dye as a result of a slow journey down the oviduct. (In fact, when assigning shell color to dark chocolate brown Marans eggs on the official Egg Color Chart which ranges from 1 which is the lightest to 9 which is the darkest, the first dozen eggs a young pullet lays aren't even considered for judging purposes.)
Why Do Fairy Eggs Happen?
Fairy eggs occur when the hen's body begins to form an egg before a yolk is released from her oviduct. Therefore, only the white (albumen) is encased inside the shell. Young layers are notorious for laying them, although I've had many, many pullets start laying normal-sized eggs right from the start, instead of starting with the tiny ones and gradually working up from there. Either way, a few fairy eggs are nothing to worry about. They're just a blip in early production. Consider them prototypes! Some hens never lay the miniature versions, while others will lay you a few fairy eggs early in their "career".
Can Fairy Eggs be Eaten?
Despite the lack of a yolk, fairy eggs are perfectly edible. However, since the majority of nutrition is in the yolk and the eggs are so small to begin with, instead of eating them, I love to simply rinse off the eggs to remove the bloom (which keeps air from penetrating the shell). Then I let them air dry until the white inside has dried up and is rattling around inside. Then the eggs can be used as kitchen decor indefinitely. You don't even need to worry about blowing out the contents inside.
Although....according to superstition, in order to protect against the evils of a cock egg, one should throw it over the roof of the house and let it smash on the ground on the other side. Up to you. Personally, no matter whether you call them wind, cock, witch, fart or fairy eggs, I recommend displaying them in a small bowl or basket on the kitchen counter!