The biggest rattlesnake is the Eastern Diamondback. There is even a rattlesnake without a rattle, the Santa Catalina Island Rattlesnake!

The Rattle: A hollow rattle on the tail makes a buzzing sound when it moves. After each molt (losing the old skin), the rattle has another section added to it. Older rattlesnakes usually have a longer rattle (unless it has been broken off).

Anatomy: Like all snakes, rattlers are cold-blooded; they are the same temperature as the environment. They continue to grow all their lives, getting bigger and bigger each year. Their scaly skin glistens but is dry is to the touch. The scales vary from yellow to brown to black, and there are dark V- or diamond-shaped markings along the back. The snake smells with its tongue and has two long, hollow fangs that inject a relatively weak venom (poison) into prey. Females give birth to about 10 live young, born without a rattle.

Hunting and Diet: Rattlesnakes are carnivores (meat-eaters). They mostly hunt at night (they are nocturnal) and can sense the heat of their potential prey. Rattlers kill prey with venom, which also contains digestive enzymes that begin to dissolve the meat even before the snake eats it. Like all snakes, they swallow prey whole, head first. The top and bottom jaws are attached to each other with stretchy ligaments, which let the snake swallow animals that are wider than the snake itself. Rattlesnakes eat rodents, lizards, and other small animals.

Predators of the Rattlesnake: Eagles and people are predators of the rattlesnake.