A Small Southeast Asian Snake Cartwheels Away From Danger

Most snakes get away from danger by slithering. A group of small snakes in Southeast Asia does something much stranger: it rolls away like a cartwheel. Dwarf reed snakes arch their long bodies into a loop and tumble end over end across the ground, head over tail, until the danger is behind them.

The roll is about four times faster than slithering

Researchers filmed the snakes from several angles to work out how the trick is done. They measured the animals rolling at up to 12.1 feet per second, or 3.69 meters per second. That is much faster than the way the same snakes normally travel, a side-to-side wriggle that scientists call undulating locomotion. Yosuke Kojima, a lecturer in the biology department at Toho University in Japan and the first author of the study, told Live Science that the snakes' fastest rolling speed was, on average, four times their normal slithering speed. "Rolling allows them to escape from danger very quickly," he said.

The head stays still while the body spins

The oddest part is what happens to the head. Rather than tumbling in a jumble, the snake keeps its head in a relatively fixed position and rotates the rest of its body around it. In other words, the head stays pointed in one direction while the rest of the animal loops around behind it. The researchers say the new study confirms the overall movement pattern seen before and reveals further details, including how the snakes keep their heads steady. The work was published in the journal Current Biology.

First spotted in Malaysia, then filmed again on Borneo

Dwarf reed snakes are secretive, often nocturnal animals that live across Southeast Asia, where birds and other snakes hunt them. They are so well hidden, usually beneath leaves or other natural cover, that people rarely notice them, though their rolls are occasionally seen. In 2019, researchers watched one species, P. longiceps, rolling in northwestern Malaysia and formally described the behavior in a 2023 study. Around the same time, Kojima's team began seeing it independently in Sarawak, a Malaysian state on the island of Borneo. "I had never seen anything like it before, and I immediately wanted to learn more about it," Kojima said.

For the new study, the team filmed the behavior many times in three dwarf reed species — P. saravacense, P. collaris and P. longiceps — between 2019 and 2022. They also watched three reed snakes from a different group, known as Calamaria, and those snakes did not roll at all.

So far, the cartwheel has been recorded in three kinds of dwarf reed snakes, all of them small, secretive and living in Southeast Asia. The snakes that share their habitat but belong to a different group simply slither away.