The 33 known species of rattlesnake are all native to North, Central or South America. They are one of the newest groups of species to evolve, as well as the most sophisticated. In addition to their potent venom and long, folding fangs, rattlesnakes have another advanced adaptation, which is their namesake rattle.
Rattlesnakes swallow their prey whole, being able to ingest very large animals, such as mice, rats, rabbits and birds. Rattlesnakes are ambush hunters, having vertically elliptical pupils that resemble a cat’s eye. Rattlesnakes have a pair of small pits located in the front of their faces that help them find their prey and also give them the title of pit viper. These pits detect the heat emitted by the bodies of predators and prey, enabling the snakes to see them in complete darkness.
Rattlesnakes give birth to live young, which are born already possessing venom and fangs and can defend themselves immediately. However, a young rattlesnake is not born with an actual rattle but has only a single segment of the future rattle on the tip of its tail. As the rattlesnakes grow and shed their skin, their rattles get longer. These rattle segments are very brittle and break periodically.