Rattlesnake adaptations include the ability to sense faint vibrations caused by prey, an extremely sensitive sense of smell, teeth that prevent prey from escaping, and a tail that rattles and scare away intruders. Rattlesnakes have highly developed heat sensors near their mouths, and their eyes are adapted for vision in dim light.
Rattlesnakes sense vibrations along the length of their bodies and then transmit these to their jawbones and inner ears. They have no external ears. Rattlesnakes smell with their tongues, and because the tongues are forked, they can tell from which direction a scent is coming. The teeth in a rattlesnake point backwards, toward the throat, so once they catch an animal, it has a hard time getting away. Rattlesnakes use the rattles at the end of their bodies to startle and frighten potential predators.
Rattlesnakes are pit vipers, which means they have two pits just under the snout, which sense body heat. They use these to locate and kill other animals. Rattlesnakes do not see well beyond about 40 feet, but they have developed elliptical pupils, which allow them to see well at night.
Like all snakes, rattlesnakes have evolved hinged jaws that allow them to eat animals much larger than their bodies. Once they have swallowed an animal, they become sluggish while they digest it, which may take days.