Chickens Lay Eggs by Forming Yolk and Egg White Layers

Female chickens lay eggs by first producing a large yellow yolk containing fat and protein, which moves through the ovaries and down the oviduct. Layers of gooey egg whites are then added around the yolk to protect it. Subsequently, the eggshell, made of calcium, is sprayed on in multiple layers to create a hard, protective shell. After this process, the egg is laid and, if fertilized, the chicken will incubate it for about three weeks until the baby chick hatches.