Why do rattlesnakes rattle before striking?

Rattlesnakes vibrate their tails to produce a buzzing sound primarily as a warning device. Rather than being aggressive, these snakes are generally shy and timid; they prefer to provide a prolonged warning rattle when they feel startled or threatened, such as when they are stepped on or molested, rather than resorting to a defensive strike.12

This behavior serves as a form of defense, signaling to potential enemies to keep their distance. The rattle itself is composed of loose, dry, horny, and hollow segments at the tip of the tail. When the snake rapidly vibrates its tail, these segments strike against one another to create the characteristic buzzing sound. While this warning is a well-known trait of rattlesnakes, other non-rattling snakes may also vibrate their tails against dry leaves to produce a similar sound, effectively mimicking the warning signal to deter predators.31