Hair and fur are essential materials in tying flies for fly fishing, providing natural movement and buoyancy. Different types of hair and fur, such as deer hair, elk hair, and rabbit fur, are selected for their specific properties. Deer and elk hair are often used for dry flies due to their buoyancy, helping the flies float on the water's surface. Rabbit fur, with its soft and supple texture, is commonly used for nymphs and streamers, mimicking the movement of aquatic insects and small fish. These natural materials enhance the fly's realism and effectiveness in attracting fish.