When you’re out herping deep in the forests of Southeast Asia, you might come across a small, slender, and oddly charming snake with a curious tilt to its head, the Pareas berdmorei, also known as Berdmore’s Snail-Eating Snake. Don’t let its delicate frame fool you; this little reptile is a marvel of natural engineering. With its asymmetric jaw and specialized diet, it’s one of the most unique snakes you’ll ever encounter in the wild.

A Specialist in the Shadows

Unlike most snakes that hunt rodents or frogs, the Pareas berdmorei has a very specific menu… snails. Over time, it’s evolved a jaw that’s unlike almost any other reptile’s. One side of its mouth has more teeth than the other, allowing it to efficiently scoop a snail right out of its shell. It’s one of nature’s rare examples of lateral asymmetry, proof that even among snakes, there are specialists that adapt in fascinating ways.

Found across Myanmar, Thailand, Laos, Vietnam, Cambodia, and southern China, the Berdmorei prefers the cool, damp, and shaded parts of the forest. It’s a nocturnal species, meaning your best chance of spotting one while field herping is after sundown. Headlamps and patience are key, these snakes move slowly and often blend perfectly with wet leaves or mossy branches.

Identification: Subtle but Striking

At first glance, the Pareas berdmorei might not look like much, its brown or grayish coloration helps it disappear into its surroundings. But under a flashlight, you’ll notice a pale underside, a distinct ridge running along its back, and eyes that seem oversized for its head. Those large eyes aren’t just for show, they give the Berdmorei incredible night vision, ideal for locating snails in the dark forest floor.

The average adult reaches about 50–70 cm in length, with a thin body that’s perfectly designed for maneuvering through leaves and low branches. They’re completely harmless to humans, in fact, they rarely even try to bite. Their defense is more about stillness and camouflage than aggression.

The Beauty of Adaptation

What makes the Berdmorei truly fascinating to herpers and biologists alike is how it has evolved to fill such a narrow niche. Its uneven jaw isn’t a deformity, it’s a perfect adaptation. Most snails coil their shells in one direction (called “dextral”), and this snake’s right-leaning jaw structure lets it feed on them with remarkable efficiency. A few species of snails have even evolved left-handed shells as a defense against these predators. That’s the kind of evolutionary arms race that makes studying and observing snakes like the Pareas berdmorei so exciting.

Herping Tips: Where and How to Find One

If you’re planning a field herping trip in Southeast Asia, particularly in moist lowland forests or hilly jungle terrain, keep your eyes peeled for these snakes near leaf litter, low shrubs, or fallen logs. They’re slow-moving and gentle, so approach carefully and respectfully. Try not to disturb them while feeding, it’s a rare and rewarding sight to see one extracting a snail with surgical precision.

Photographers often appreciate how cooperative Berdmorei can be during shoots. They don’t spook easily and tend to hold still, making them a great subject for macro or close-up photography. Just remember: patience is everything. Sometimes, you’ll spend hours scanning the forest floor before you notice a small, motionless curve of scales that turns out to be your prize find.

So next time you’re out in the jungle at night, flashlight in hand and rain dripping off the canopy, look closely at the leaves beneath your feet. Somewhere out there, a little brown snake with an uneven jaw is gliding silently in search of its next snail, a true symbol of evolution’s creativity.