Sheep

The sheep is a medium-sized farm animal raised by people around the world. Sheep are mammals, which means they have fur, breathe air, and feed their babies milk. Most sheep are covered in a thick coat of curly wool. Adults usually weigh between 100 and 350 pounds, depending on the breed. A baby sheep is called a lamb, a female is a ewe, and a male is a ram.

Sheep were one of the first animals that humans ever tamed. People in the Middle East began raising them around 10,000 years ago, about the same time they first started farming. Today there are more than one billion sheep on Earth. China, Australia, and India keep more sheep than any other countries.

People raise sheep for three main things: wool, meat, and milk. Wool comes from the thick, curly hair that grows on a sheep's body. Once a year, a farmer shears the sheep by cutting off the wool with special clippers. This does not hurt the sheep. One sheep can grow between 2 and 30 pounds of wool each year. The wool is then cleaned, spun into yarn, and made into sweaters, blankets, and socks.

Sheep are plant eaters. They spend most of the day grazing on grass, clover, and other low plants. They have a special stomach with four parts that helps them digest tough plant food. After swallowing, they bring the food back up and chew it again. This is called chewing cud.

Sheep are famous for following each other. If one sheep moves, the others usually follow. This is not because sheep are foolish. Staying close together is how they protect themselves from predators like wolves and coyotes. A single sheep alone is an easy target. A tight flock is much harder to attack. For thousands of years, farmers have used trained dogs, called sheepdogs, to guide flocks and keep them safe.

Scientists who study sheep have found that they are smarter than most people think. Sheep can recognize the faces of at least 50 other sheep and remember them for two years. They can also recognize human faces and tell the difference between a happy and an angry expression.

Sheep have shaped human life in surprising ways. Wool helped people survive cold winters long before heated homes existed. Sheep grazing changed the shape of whole landscapes, from the hills of Scotland to the plains of New Zealand.