Rattlesnakes! The word alone fills most people with fear and anxiety, because they have no experience in dealing with snakes. Yet we should learn to appreciate the rattlesnake as one of the most efficient and specialized predators on Earth. Many rattlesnakes struggle to survive as humans move in on their habitat. Rattlesnakes are known for their relatively heavy bodies and diamond-shaped heads. They are considered to be the newest or most recently evolved snakes in the world. Rattlesnakes have either a rattle or a partial rattle made of interlocking rings, or segments of keratin, the same material our fingernails are made of. When vibrated, the rattle creates a hissing sound that warns off potential predators.