Many different species, including birds, reptiles and fish, lay eggs, and humans are eating eggs for thousands of years. Most eggs eaten by humans, including birds and turtles, have thin membranes that appear as the layers of skin. Eggs contain various proteins, like calcium, magnesium, iron, carbonate and salt.

Putting an egg in a glass of water is a simple way to test if the egg is still fresh or not.

Egg yolk contains almost 40 percent of an egg's protein. The protein in raw eggs is only 51% bioavailable, while boiled eggs are almost 91% bioavailable.

In 2010, a hen from the United Kingdom hatched an egg that measured 9.1 inches in diameter. This beat the previous record-holder which was only 8.6 inches in diameter.

A hen takes up to 26 hours to develop an egg. Once she lays an egg, the evolution of a new egg normally starts within half-hour.

Here are some unusual facts about

Eggs

1. 1 in every 20K eggs may contain bacteria

2. Putting eggs in the fridge is not essential

3. You don't have to worry about cholesterol

4. Chickens do not produce one egg at a time

5. Try not to depend upon eggs for omega-3s

6. Chickens can lay an egg inside another egg

7. A hen begins laying eggs at 19 weeks of age

8. A normal hen lays 300 to 325 eggs every year

9. The white stringy thing is a sign of a good egg

10. Not all eggs within the carton are off same size

11. Egg yolk color does indicate nutritional differences

12. It takes 24 to 26 hours for a hen to develop an egg

13. Eggs are one of the few dietary sources of Vitamin D

14. There is more protein in a cooked egg than raw eggs

15. Concerning their body size, kiwis lay the largest eggs

16. 'Cage-free' eggs may come from hens that live in cages

17. Egg shell color doesn't indicate nutritional advantages

18. Eggs have about 6 grams of high-quality protein in them

19. The yolk and the whites have the same amount of protein

20. The hen must eat 4 pounds of feed to make a dozen eggs

21. A breed of catfish lays its eggs with the eggs of the cichlid fish

22. How thick an eggshell is depending on the age of the laying hen

23. Chicken earlobes can guess what shade egg they are going to lay

24. Three British men went o Antarctica to examine penguin eggs

25. Every year World Egg Day is celebrated on 2nd Friday in October

26. The eggshell may have as many as 17,000 tiny pores over its surface

27. The most expensive egg ever sold was the Faberge “Winter Egg” in 1994 for $5.6 million