Fiber is a threadlike material that can be found in a natural or artificial form. Natural fibers come from various animals and plants and can even be produced by insects. These fibers have been used since prehistoric times and are currently produced today. The most commonly used natural fibers are linen, wool, silk and cotton. They were woven together to create fabrics for clothing and other items. A natural protein fiber, called wool, was discovered before 10,000 BCE and woven into cloth around 1900 BCE. Wool comes primarily from sheep, but it is also found in other animals such as llamas, alpacas, camels and goats. Northern European tribes spun wool using a crude spindle, which is a stick with a ring of stone or clay connected to the end to make thread. They also turned wool into fabric by weaving the thread in a criss-cross style. By 8,000 years ago, some humans domesticated sheep specifically for wool production and other uses. By 4,000 BCE, the city of Babylon, also known as the “Land of Wool,” had bought and sold woolen fabrics important to their society. Over the years, spinning and weaving machines were constantly improved, such as the spinning machine built in 1767 with many spindles placed side by side allowing it to operate 120 spindles at a time. Wool weaving became more machine-based rather than traditional hand weaving (“History of Wool,” n.d.). In order to create the fiber wool, there is a process of cutting the animal's hair which is usually done manually by a shearing specialist. After cutting, the shorn wool is cleaned and brushed to straighten the fiber strands by hand. The wool is then placed in a carding machine where it passes through numerous pile rollers and is spun. The carding process separates the wool into small pieces and cools it into spools at the end of the machine. Soon the wool was turned into yarn and woven into fabric. Before this mechanical process, many women known as spinsters took on the task of manually turning wool into fabric. Wool is commonly used to create cool weather sweaters and coats (“History of Fibers,” n.d.). The fiber repels water well and the fabric is dry in humid or wet weather. The downside to wearing wool is that it attracts moths and carpet beetles which feed on the fabric..