Would you like to eat this snake? What if it was dead, bleeding from the mouth and covered in feces? What then?

At the beginning of his research, Vukašin Bjelica fought with a hissing grass snake he caught and was delighted. But when Bjelica tried to take a close-up photo of the violently fighting snake, the snake suddenly went limp. Its mouth stood open and completely lifeless. “I was heartbroken,” he said. “I thought I had somehow accidentally injured and killed it.” Bjelica dropped the snake back to the ground and was wondering what to do when the snake suddenly came to life – it clicked its tongue, raised its head and darted of that. “You can imagine my surprise,” Bjelica said.

He later learned that the grass snake’s behavior was logically called “feigning death.” When Bjelica began his doctoral work at the Zoological Institute of the University of Belgrade in Serbia, he focused his research on dice snakes, a common aquatic relative of grass snakes with a unique approach to cheating death. Hissing, fighting and finally going limp are not enough for the dice snake. She ups the blood stakes by smearing herself with feces and smelly musk, after which the snake may dribble blood from its mouth. The delayed bleeding made Bjelica curious. Feigning death, a high-risk behavior that puts the snake at high risk of being eaten if its ruse is exposed, usually occurs as a last resort after a snake has tried other defense mechanisms. “Then, after entering this rather enigmatic apparition, suddenly there is this appearance of bleeding,” Bjelica mused. He wondered whether the bleeding made the snake’s act more convincing, a question he put to the test in a new essay Biology letters.

Bjelica focused on a population of dice snakes on the island of Golem Grad, a nearly 50-hectare island in a lake in North Macedonia. In particular, the island contains the ruins of some old churches and around 10,000 dice snakes. Most notable, however, are Golem Grad’s snakes for their tendency to feign death and bleed spontaneously. Behaviors more commonly observed in this dice snake population than others. On Golem Grad, dice snakes are found in olive green, spotted or a darker melanistic color, and their abundance makes them easy to spot and catch. “Sometimes you see them lying on a rock in the sun and you can just grab them,” Bjelica said. “Or they’re resting on a branch and you just climb up and get them.”

Over the course of a year, Bjelica and colleagues caught 263 unique dice snakes on Golem Grad by snatching them from their rocks and branches or even swimming around the lake. He wore protective gloves — not for the snakes, which are nonvenomous, but for the island’s sharp rocks and thorny Mediterranean vegetation. The island is also home to another, actually poisonous snake: the horned viper, named for the distinctive horn on its snout.

After capturing a snake in the midsection, the researchers held the snakes behind their heads and over their cloacas, alternating between pinching and stretching. The behavior was intended to mimic one of the snake’s predators, such as one of the islands’ snake-eating birds. “Pinching was intended to simulate the claws grasping the snake, while stretching was intended to mimic the bird stretching the snake to get to the large organs such as the liver,” Bjelica said. After the handling ritual was completed, the researchers placed the snake on its back on the ground and fled out of sight, mimicking a predator’s hesitation to eat its prey. They estimated the snake’s reaction from the moment it was left alone, observing how the animal feigned death and how.

Nearly half of the snakes smeared themselves with musk and their own excrement, a strategy that can convince the predator that the snake is inedible – it literally smells and tastes like shit. Watching it was an unsurprisingly stinky experience. “The amount of feces can be extreme,” Bjelica said. “In most cases, it makes sense to change your wardrobe after each field day.” And just over 10 percent of the dice snakes spit out blood, a behavior that Bjelica finds “always exciting.” The bleeding always occurs around the mouth and, fortunately for researchers, is not sprayed in the direction of a predator. “The blood comes out slowly, initially in individual spots, then it groups into larger puddles,” he said.

Although all the snakes played dead, some engaging in the act for up to 40 seconds, the snakes that used musk, poop and blood in their performances spent an average of two seconds less feigning death. That may sound like an insignificant amount of time, but for a snake staring down the jaws of a hungry bird, it can mean the difference between life and death. To feign death, the snake must lie with its delicious, soft belly facing upwards to be inspected by its greatest enemy. The more convincing a snake’s act, the less time it has to spend in mortal danger, the researchers suspect.

But they are still left with questions. Bjelica wonders about the chemical composition of the snake’s musk and blood. “Are they harmful to the predator or just tasteless?” Researchers don’t know whether a dice snake’s sip of blood is a visual signal, a chemical signal, or both. They don’t even know the mechanism by which a living snake can drip blood from its mouth. But from Bjelica’s perspective, the most important takeaway from the research is that the death-feigning depiction of the Dice Snake on Golem Grad is a multi-stage spectacle of blood and guts and should be examined as such. Regardless of what dice snakes do elsewhere in Europe, Golem Grad has set the bar high for the ancient technique of faking one’s own death. Other death deceivers, beware! Sometimes bonding with the teeth is the only way to stay alive.