The “poison” of rattlesnakes is used to catch prey and for protection. Some people think that rattlesnakes go around biting everything in sight, but this is not true. They only use their “poison” to catch their food—or when they feel they are in danger.

Rattlesnake “poison” is called venom. The venom is made in special glands inside a rattler’s head, and it is injected into prey through hollow fangs. The snakes can control the amount of venom that they put into prey. They usually inject just enough venom to kill the prey quickly.

The fangs of rattlesnakes are hollow, like the needles that doctors use to give injections. They have sharp, pointed ends that can break through skin.

A rattlesnake can strike prey that is very close to its head from almost any position. But to strike an animal that is more than a few inches away, it throws the front half of its body forward, then sinks its fangs into the prey.

Venom is pushed through the hollow fangs and into the prey. The amount of venom that is injected depends on the size of the prey. In general, a rattlesnake will use less venom for smaller prey and more venom for larger prey.

The fangs of a rattlesnake are usually folded inside the mouth. The fangs move forward when the snake strikes.

The strike has three stages. First, the body lunges forward with the jaws only half open. The fangs are still folded up inside the mouth.

Just before the mouth reaches the prey, the fangs swing down. They break through the skin and begin to sink into the body of the prey.

As the fangs sink deeper, the snake begins to inject the venom. The deeper the venom is injected, the better chance it will have to kill the prey.

The venom is made and stored inside a special gland in a rattlesnake’s head. When the rattler strikes, strong muscles around the gland push the venom through a tube and into the fang. The muscles can push very hard, to make the venom move very fast.

You can see how the muscles work to squeeze the gland if you squeeze a syringe filled with water. The harder you squeeze, the faster the water squirts out.

Rattlesnakes have very long fangs. A few kinds of rattlers have fangs that are more than an inch long. This is why rattlers fold their fangs. When a snake closes its mouth, the fangs would never fit inside if they could not be folded.