The coats of dogs are just as diverse as the breeds of animals that possess them. Variations in color are tremendous and are usually a central consideration in determining a breed. Hair types also vary significantly, but are usually broadly categorized as short, medium, or long. The hair may also be fine or coarse, and coats are usually thickest among animals living in cold areas. In most locales, dogs begin shedding in the spring, thinning out the coat as warmer weather approaches. Though there is not a significant demand for products made of dog hair, some people spin excess dog hair into yarn and utilize it to create knit items.