Rattlesnakes -- or rattlers -- are dangerous and venomous. Rattlesnakes are famous for the rattles at the end of their tails. Rattlesnakes' rattles are made up of a series of loosely connected yet interlocking rings, and they make a buzzing sound when shaken.
Living in arid areas of Americas (such as the Great Basin Desert in the U.S.), rattlesnakes belong to a snake family called the viper. As all vipers do, rattlesnakes have two long, hollow fangs in their upper jaws. Usually, rattlesnakes and their viper relatives don't like to show off their teeth, so they fold them back in their mouths. Yet, when vipers are ready to strike, either for catching a prey or for self-defense, they open their mouths wide, swing forward their fangs, and give their target a deadly injection of venom!