Strange Abnormalities in Chicken Eggs

Because they come from an organic source, chickens' eggs are blessed with variations. Because each egg is laid by an individual chicken and carries its own unique cellular DNA, no two eggs will ever be exactly alike. Still, these variations are so limited as to be noticeable to humans only on a microscopic level, and we don't often think of eggs as individual cells with their own genetic sequence.

Some eggs are unusual enough that they stand out, even to our eyes, as anamolies. Most often, major abnormalities in chicken eggs occur only when the hen who lays them is very young, because her hormones have not yet regulated to produce fully developed eggs. Just as human girls can menstruate without ever having ovulated, chickens will occasionally lay eggs that look extremely different than other eggs because of unusual variations in a hen's hormones.

Eggs with No Shells

Rarely, a chicken with an unusual endocrine system may "accidentally" lay an egg without a shell. Don't worry: this doesn't mean that the egg comes out as a globby, sticky mess. The egg still has a membrane that holds the liquid in, and it feels something like a water-balloon. These eggs are perfectly edible and do not indicate a health problem in the hen. If the egg had been fertilized, a baby chicken could not have likely hatched from it, because it wouldn't safely retain heat or protect the embryo.

Eggs with No Yolks

Occasionally, some young hens will lay eggs that have no yolk whatsoever, only a small amount of grayish tissue. These eggs, historically called "cock eggs" because som people erroneously believed that they were laid by roosters, are now often jokingly called "fart eggs" by people who raise chickens and encounter these unusual eggs with some regularity.

Eggs with Multiple Yolks

Double-yolked eggs are not extremely uncommon, and even occasionally find their way into grocery-store egg cartons. This is the result of a chicken ovulating twice, and, as with many of the other abnormalities, occurs most often in immature or very young chickens. Most multi-yolked eggs contain only two yolks, but eggs with as many as nine have been reported.

Eggs inside of Eggs

Double-shelled eggs are very rare, so no one is completely certain how or why they occur. Some veterinarians think that chicken's body might become "confused", leading it to coat the egg yolk in albumin (or egg white) twice, complete with an extra shell. Most often, these double-shelled eggs appear relatively large, and, when they are cracked, a smaller egg is inside. The small egg usually contains no yolk.

Strangely Shaped Eggs

Eggs that are elongated or unusually spherical are not all that unusual, but some very strange anamolies sometimes occur, as well. Spoon-shaped eggs, eggs with long tail-like appendages, and other very bizarre abnormalities, have been known to occur on very rare occasions.No one is entirely sure why these occur, but they provide fascinating insight into the biology of chickens.