Domesticated sheep currently number over 1 billion animals. China has the largest population of sheep in the world. New Zealand however, has the highest density of sheep per area. In 2006 there was approximately 10 sheep per person living in New Zealand. They were one of the earliest animals to be domesticated for agricultural purposes. They are raised for fleece, meat, and milk, as well as being kept for pets. Sheep wool is the most widely used animal fiber in the world. Sheep will typically live 10-12 years, with a ewes productivity peaking between 3-6 years of age. Sheep have a strong flocking instinct and will often not act independent of each other, they band together as a defense mechanism against predators. They depend heavily on sight and have excellent peripheral vision. Their field of vision is around 300 degrees. In 1996 sheep became the first mammals to be cloned when Dolly was created from a somatic cell. They can recognize up to 50 different faces, and have best friends. There is evidence of wool being used as far back as 10,000 BC, and by the time the Romans invaded Britain in 55 BC the wool industry had already been developed. In the 1400’s Spain’s wool industry funded most of their expeditions including Christopher Columbus’s voyage to the New World. Columbus himself actually came from a family of wool traders. Until the 1700’s in Spain exporting sheep was a crime punishable by death. In the 1600’s to protect England’s wool industry King George III banned the export of sheep to the Americas and wool trading in the colonies. This was one of the actions that led to the American Revolution. As well during World War I the White House lawn was “mowed” by a herd of sheep. There are approximately 900 different breeds of sheep worldwide.