Most species live near open, rocky areas. Rocks offer them cover from predators, plentiful prey (e.g. rodents, lizards, insects, etc. that live amidst the rocks), and open basking areas. However, rattlesnakes can also be found in a wide variety of other habitats including prairies, marshes, deserts, and forests.
Baby rattlesnakes and the Mojave rattler are the exception; they have venom which contains more neurotoxic properties than hemotoxic which makes them very dangerous. The sea snake, coral snake, and cobra family of snakes also have venom with dominant neurotoxic characteristics. (Brown, 1997).
Rattlesnakes are venomous snakes. They produce very strong hemotoxic venom (which destroys blood cells and vessels). It is used for hunting and for defense against predators. Rattlesnake bites are fatal for humans if not treated with antidote immediately.