June 13, 2025, 2:19 pm | Read time: 4 minutes
Snakes are generally silent creatures, but there is an exception: the rattlesnake. These reptiles use a tail rattle to draw attention and warn others—often successfully. But how is the rattling sound produced? Are there actually small particles in the snake’s tail, like in a real rattle?
The rattlesnake is likely one of the few snakes you hear before you see. Well camouflaged, these animals prefer to spend their days lurking on the sandy floors of the deserts or steppes of Central America. Their venom is so potent that it can even kill humans. Nevertheless, these snakes have developed an effective defense mechanism to warn potential attackers: They produce a loud rattle with their tails. But how exactly is this sound created? Are there small particles at the end of the tail, like in a real rattle? And if so, how does the snake form them?
Why Do Rattlesnakes Rattle?
Even without their rattle, probably no one would quickly think of touching a rattlesnake—and that’s a good thing because the venom of these animals is very strong and can also kill humans. So why is another defense mechanism needed? The answer is simple: The snake saves energy and venom. Usually, when rattling, the animals only move their rattle and remain in their position. This behavior is often enough to make potential attackers—especially larger mammals—retreat.1
The warning is so successful that other snakes and even birds imitate the sound of rattlesnakes to protect themselves from predators. However, there are also animals that are not deterred by it. Foxes, coyotes, and birds of prey, in particular, do not shy away from rattlesnakes, and there are even reports of domestic dogs and cats killing and eating the snakes. The venom is only deadly if it enters the bloodstream.
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How Do Snakes Produce the Rattle?
This question seems to intrigue many people. On social media, there are several videos where the tail rattle is cut open to explore its contents. Fortunately, these are always specimens of already deceased animals that were legally acquired. But what is found inside the tail rattle? Nothing!
The rattling sound does not come from small particles like in children’s rattles but from many layers of horn scales lying within and against each other. You can imagine the structure somewhat like a Matryoshka doll. These are the wooden, colorfully painted, nested Russian dolls. Only the layers are much thinner and more flexible, so when the tail rattle is shaken, an impressive sound is produced.
How the Rattle Is Formed
The horn scales are the scales at the tip of the tail, which are the only ones not shed during molting. The tail rattle is not present from the start. It develops over the course of a rattlesnake’s life and is extended with each molting. And if anyone is wondering whether the age of the snake can be determined by the scale layers, like with tree rings, I must disappoint you. Snakes molt several times a year. Additionally, the end segments of the rattle can occasionally break off, so no age indication is possible from the rattle segments or horn layers.
Does That Mean Baby Snakes Can’t Rattle?
Indeed, newborn rattlesnakes (yes, rattlesnakes are born alive and do not hatch from eggs) are not able to rattle. In a video from Hagenbeck Zoo, now more than twelve years old, you can even see that baby rattlesnakes only have a small nub at the end of their tail. Nevertheless, they already show the typical tail movement.
It’s hard to say at which molting the young snakes can produce a rattle that has a deterrent effect. The main defense strategy of rattlesnakes is their camouflage through their coloration and behavior. They also often hide under stones or in bushes. Only when this passive defense does not work, do the animals start rattling with their tail.
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Where Do Rattlesnakes Live?
Those living in Europe will probably never experience the rattle of a rattlesnake in the wild—or, at most, with animals in captivity. A total of 29 species live mainly in Central America—especially in Mexico. No wonder: Rattlesnakes love dry and warm areas. Therefore, they are usually found in deserts or steppe regions. But rattlesnakes are also at home in Canada and Argentina. However, only a few species are found there.2, 3
About the Author
Dr. Saskia Schneider is a biologist with a Ph.D. During her studies at the Free University of Berlin, she focused primarily on zoology and animal behavior.