From jewelry to tattoos, the picture of a snake that bites its tail is engrained in many of our minds. But experts argue this is just symbolism we've inherited from ancient mythology and not actually a concern of herpetologists and snake scientists alike — with a couple of exceptions.
Rooted in Myth: Ouroboros and Hoop Snakes
The visualization of a snake biting its own tail is deeply rooted in myth. In ancient mythology, a tail-eating snake is called an ouroboros, from the Greek word that literally means tail-eating. As an icon, it represents the concepts of continuity, eternity, rebirth and the cycle of life.
It has been adopted by various cultures and traditions throughout millennia, including Ancient Egypt, Greece and Norse mythology. Similarly, in more recent Northern American folklore, there's a hoop snake legend — a snake bites its own tail, makes a hoop and rolls around like a wheel to catch its prey and terrorize any attackers.
"Snakes really seem to have a lot of superstitions associated with them," says Matt Goode, an assistant research scientist at the University of Arizona School of Natural Resources and the Environment. "They're so different than we are."
Strange Snake Behaviors: Trauma and Distress, or Simply a Mistake
The term ouroboros has seeped into reptilian scientific literature, too. For instance, researchers named the genus of African armadillo girdled lizard the Ouroborus cataphractus because of how they coil up and bite their own tail to form a protective armadillo-like ball. Little scientific evidence shows snakes bite their tails or try to eat themselves.
Sure, there have been a couple of reported incidents of snakes munching down on their own tails while in captivity, like the famous female Albino Western Hognose biting her tail in the UK in 2014, but this isn't something scientists are concerned about as snake behavior in the wild.
"What people see a lot are videos of snakes biting themselves on the body. And the terrible news of all of this is that it's often a snake that has been hit by a car or something like that," says Bryan Maritz, senior lecturer at the Department of Biodiversity & Conservation Biology at the University of the Western Cape. "When snakes are in excruciating pain, they just lunge out and they bite. If they're really in trauma, you sometimes see them biting their bodies, and it's really quite horrible to watch."
Read More: 10 of the World's Deadliest Snakes
Why Does a Snake Bite Itself?
Atop trauma or intense stress, scientists speculate that a snake biting its tail may have mistaken itself for prey because it's hungry or got confused while attacking another snake.
"Snakes aren't brilliant, right? Then you might have a snake that's eating another snake. And then it accidentally just starts swallowing what it thinks is the other snake and it could be its tail," says Goode. "I could see that possibly happening just because they have such a strong feeding response."
Some snakes go as far as eating other snakes — especially certain species of cobras, whose diet mainly consists of other snakes, even venomous ones. "King cobras in India are one of those," says Goode. "They will sometimes eat an individual of their own species."