Hair is a threadlike growth from the skin of a mammal. Seta is the name used in a bristle like growth hair on plants and the bodies of insect and certain animals without backbones example of "Seta" is found in a caterpillar. Hair color, texture and density varies according to species, the individual and in the part of the body where it grows.

Hair Structure : Hair structure grows out of small cavities in the skin known as hair follicles. In some mammals several hairs grow from each follicle. A small projection called a papilla, containing nerves and blood vessels, lies at the bottom of the follicle and nourishes the hair cells. Each hair is supplied with oil by sebaceous glands in the skin. An involuntary muscle, the arrector pili, attached to the follicle makes the hair "stand up" in response to cold, or to fear and other emotional stimulation. In humans this muscular response cause "goose flesh."

Hair Growth : As new hair cells formed the old cells are pushed above the skin surface where they die. Only the root of a hair is living, that is the reason why it does not hurt when hair is being cut. Cutting the hair will not make it grow faster nor thicker, as other people believed. The rate at which the hair grows has been measured and found to be about 1.5cm (half an inch) a month. The hair doesn't grow at the same rate throughout the day but seems to follow certain rhythm. At night, the hair grows slowly, but as day begins, it speeds up. The growth of hair is at its greatest at around 10 and 11 am, then it grows again slowly and speeds up again around 4 and 6pm, then slows down again. The growth period of shorter body hairs, such as eyelashes, is only a few months. At the end of the growing period, the old hair falls out, and a new one starts to grow. In some mammals they shed all their hair at certain times of the year and grow a new coat.

Hair Pigment / Color : The graying of hair, is due to pigment loss, causes are hereditary, illness, stress. It is believed that adding healthy oils on the diet can prevent premature graying of hair and even baldness.

Hair is straight or curly depending oh the shape of the follicle from which it grows.

• Straight hair -it grows from completely round follicles.
• Wavy hair - it grows from oval follicles.
• Very Curly hair - it grows from flattened follicles.

Uses of Human and Animal Hair:

1. Human hair is used into making wigs, hairnets and toupes.
2. Animal hair is used in upholstery stuffing, in plaster, in manufacturing of felts (thick fabric made of fibers of wool) or hats, rug pads and pennants (long pointed flag). Animal pelts (animal skin especially with fur still on it) are used in fur coats.

• Wool (thick soft hair) from sheep, goats, vicunas, alcapas, and llamas is used in making textiles and carpets.
• Horsehair - the bowstrings of violin is a horsehair