The Domestic Sheep, Ovis aries, is the most common species of the sheep genus (Ovis). It is a woolly ruminant quadruped which most likely descends from the wild mouflon of South Asia. Sheep breeders refer to female sheep as ewes, intact males as rams, and castrated males as wethers. Yearlings are called hoggets and young sheep are called lambs. Domestic Sheep are now found all over the world, but they are declining in numbers in the U.S. because it is becoming economically unviable to raise sheep for their wool.
There are many breeds of sheep, but they are generally referred to as sub-class rather sub-species. Sheep are bred for both their wool and their meat. Some popular wool breeds are Merino, Romney, Lincoln, and Rambouillet. Drysdale and Herdwick breeds are specifically for carpet wool. Popular meat varieties are Suffolk, Hampshire, Dorset, Columbia, and Montadale. Some sheep are used for both their wool and meat. They are referred to as dual-use breeds. A few of these are Coopworth and Corriedale. There are sheep bred for their leather. They are called true hair sheep. Hair sheep are becoming increasingly more popular for their no-shear aspects.
Raising sheep was and is important to farmers in many economies, given that sheep can produce milk, wool, sheepskin, and give us meat. Some countries that are major sheep breeders are China, Australia and New Zealand, Argentina, Uruguay, and Chile. Some smaller countries such as Wales and
Sardinia has sheep breeding as its principal industry. In the UK, the importance of the wool trade was so significant that in the upper chamber of parliament (the House of Lords), the Lord Chancellor sits on a bench known as the Woolsack. This is, as its name suggests, a sack of wool and confers the importance of the wool trade to the English economy at the time of its installation many centuries ago.
Some breeds of sheep exhibit a strong flocking behavior. Flocking is advantageous to non-predatory animals. Stronger animals fight their way to the center of a group where they are provided greater protection from predators. However it is disadvantageous when food is limited and sheep are prone to overgrazing. Sheep are one of the many animals that can display a preference for homosexuality. It occurs in about eight percent of the rams on average. Its occurrence does not seem to be related to dominance or flock hierarchy; rather the rams typical motor pattern for intercourse is merely directed at rams instead of ewes.
Sheep have horizontal slit shaped pupils. The narrower the pupil, the more accurate the depth perception of peripheral vision is; so narrowing it in one direction would increase depth perception in that plane. Animals like goats and sheep may have evolved horizontal pupils because better vision in the vertical plane may be beneficial in mountainous environments.