Rattlesnakes: The Animal and the Venom (Part 1 of 2).

In brief: All rattlesnakes are venomous, but | they vary in degree of dangerousness. They also vary in length, color, and markings. Because they like warm weather, most of them live in the southern states, from California to Florida. Unfortunately, it is difficult to identify rattlesnakes, because harmless snakes share some of their characteristics. The primary purpose of the rattlesnake's venom is to obtain food; to a lesser extent it is used as a defensive tool. In offensive bites the volume of venom is well controlled, while in defensive bites it is not. Sometimes no venom is injected. Human reactions to envenomation include pain and swelling, hypotension, bleeding, and neurotoxicity.