The Smallest Snake In The World Is A Sub-4-Inch, Non-Venomous ‘Threadsnake' — And It's As Thin As A Strand Of Spaghetti

Forbes

23-04-2025

Among over 100 species of threadsnakes, the Barbados threadsnake stands out as the smallest serpent ... More ever recorded.
On June 9, 2006, herpetologist Blair Hedges and his wife, Carla Hass, were turning over rocks in a patch of secondary forest near Bonwell in Saint Joseph, Barbados, when they found something extraordinary.
Curled under a rock was the tiniest snake ever recorded — slender as spaghetti, small enough to coil on a U.S. quarter. It was a species never formally described. Hedges originally named it Leptotyphlops carlae after Carla, but subsequent genetic and morphological studies placed it in a different genus within the same family. Today, its valid scientific name is Tetracheilostoma carlae, though it's commonly known as the Barbados threadsnake.
The snake belongs to a strange and secretive family known as 'thread snakes' or 'slender blind snakes' — serpents so thin, small and reclusive they're often mistaken for worms at first glance. These slithery reptiles belong to the family Leptotyphlopidae, which includes over 100 known non-venomous species, most barely longer than a pencil. While they aren't truly blind, their vision is atrocious, and their eyes — tiny and covered by translucent scales — are more vestigial than functional. They're a fossorial species, after all, spending most of their lives under the ground, where darkness is the norm.
These worm-like snakes feed on soft-bodied prey like ant and termite larvae. They lack fangs, venom glands or the elaborate strike mechanics of their larger cousins. Instead, their bodies are built for stealth — with smooth scales, narrow heads and a habit of disappearing before you even realize they were there.
(As an aside, the largest snakes have historically relied not on venom or striking, but on squeezing their prey to death. Read this to learn about one such ancient, real-life monster from India's past.)
The 2006 discovery of Tetracheilostoma carlae also helped untangle a century-old taxonomic mix-up.
As Hedges studied the snake he and Carla had collected in Barbados, he began examining museum collections to see if it had ever been encountered before. It had, at least three times. But no one had realized what it was.
One specimen, collected as far back as 1889, had been sitting in the Natural History Museum in London, long misidentified as a relative from another island. Another, gathered in 1963 near Codrington College in Barbados, had also been confused with Leptotyphlops bilineatus, a species from Martinique.
But the most puzzling case came from the California Academy of Sciences (CAS).
A specimen labeled CAS 49279, collected in 1918 by zoologist W.K. Fisher during the Barbados-Antigua Expedition, was listed as coming from 'St. John,' Antigua — which, if it referred to St. John's, the capital of Antigua and Barbuda, would have been miles from where the snake actually lived.
Yet its physical traits matched the 2006 discovery from Barbados, not any known Antiguan species. Hedges investigated further and noticed something was off: fieldwork during that expedition had indeed taken place in St. John Parish, Barbados. Fisher's other reptile specimens from Antigua were all from English Harbour and Monk's Hill, not St. John's. The snake, it seemed, had simply been mislabeled by a geographic error that left the species misfiled for nearly a century.
Simply put, the world's smallest known snake had been hiding in plain sight for over a century — preserved in jars, waiting for someone to connect the dots.
The longest snake in history is the Titanoboa, which is estimated to have grown to 47 feet. At full length, Tetracheilostoma carlae — though still a snake — measures just over 0.3 feet.
It looks like an earthworm, but it's a fully grown snake. The Barbados threadsnake is built not to ... More be seen, but to vanish into soil.
Its body is uniform dark brown, featureless and smooth, with no neck or visible head-shape to speak of. The tail ends in a tiny harmless spine. Just like a common earthworm, its entire look is engineered for disappearing into soil.
It feeds almost exclusively on termite larvae, slipping unnoticed through nests deep underground. And when it reproduces, it lays a single, narrow egg — just 2.2 millimeters wide and 13.7 millimeters long.
Its range is just as narrow. This species is known only from a small upland patch in eastern Barbados, near Bonwell — a remnant of older terrain surrounded by dense development. Barbados is one of the most densely populated countries in the Western Hemisphere, and little original forest remains.
In his 2008 paper describing this species, Hedges estimated the snake's total range at under 50 square kilometers. Complicating matters further is the arrival of Ramphotyphlops braminus, the invasive flowerpot snake, now widespread on the island. Though it's unclear whether the two compete, the presence of a globally invasive cousin adds uncertainty to an already fragile outlook.
For over a century, the world's smallest known snake slipped past scientists, mislabeled and overlooked. Today, it risks vanishing again — not from obscurity, but from the erosion of the one small world it calls home.
Barbados has lost most of its natural forest to human overpopulation, putting the Barbados threadsnake at risk. If that makes you reflect on your own place in nature, consider taking the Connectedness to Nature Scale, which is a way to measure that feeling scientifically.