Wool comes from animals such as sheep, goats, alpaca and rabbits. Sheep are the most common source of wool in clothing and household items, and several breeds are raised for their coats.
Wool differs from animal fur in two ways. Wool is crimped rather than straight, which means that it curls and bends. Also, the wool shaft is covered with overlapping scales, making wool more resistant to water than fur. Most wool is harvested in the early spring when the animal still has its heavy winter coat, but while the weather is warm enough so that the animal doesn't need the extra insulation.