Young Brunette Girl At Home On The Fur Carpet

• Ground hair or undercoat or down hair — the bottom layer consisting of wool hairs which tend to be shorter, flattened, curly, and denser than the top layer. Its principal function is thermal insulation and thus thermoregulation.
• Guard hair — the top layer consisting of longer, often coarser, straight shafts of hair that stick out through the underfur. This is usually the visible layer for most mammals and contains most of the pigmentation. It protects the underfur from outside factors, such as rain, and is thus often water-repellent.
A third layer, the awn hair, may also exist. It is intermediate between the two others.