Can't remember if an egg is fresh or hard boiled? Just spin the egg. If it wobbles, it's raw. If it spins easily, it's hard boiled.

A fresh egg will sink in water, a stale one will float.

Eggs contain all the essential protein, minerals and vitamins, except Vitamin C. But egg yolks are one of few foods that naturally contain Vitamin D.

The colour of the egg shell is not related to quality, nutrients, flavour or cooking characteristics. White-shelled eggs are produced by hens with white feathers and white ear lobes.

Brown-shelled eggs are produced by hens with red feathers and red ear lobes. Brown egg layers usually are slightly larger and require more food, thus brown eggs usually cost more than white eggs.

China produces the most eggs, at about 160 billion per year. In the US, about 260 million hens produce more than 65 billion eggs per year. A hen can lay about 250 eggs per year.

An egg shell has as many as 17,000 pores over its surface.

There are 150 species of chicken. Chicken are descendants of the red jungle fowl (gallus gallus spadiceus) that lives in Asia.

The chicken is one of the first domestic animals, appearing in China around 1400 BC.