Its tail has a bright yellow or whitish tip, and the snake can move its tail so that it resembles a wriggling worm. Since many of its favorite prey feed on worms, they are tricked into approaching or even attacking the lure, and then the snake can strike and inject its deadly venom on the unsuspecting would-be predator. Although Cantil vipers are not the only snakes that use their tail to trick prey, they are possibly the best known for it.