Various species of pit vipers are found throughout North and South America. They live in a variety of habitats, including forests, deserts, and semi-aquatic environments. They are semi-social snakes, and defend each other's young. They may live between 10 and 30 years. Most species give birth to live young.
Some species of black pit vipers are extremely aggressive. Others are shy. They may bite for several reasons, including scaring off an attacker, defending their young, and to defend themselves.
Generally, pit vipers are found in two main groups. The New World group includes species found in North and South America. The Old World group includes species found in parts of Europe and Asia. There are more than 155 species of pit vipers worldwide.
