Here is a fact that sounds wrong the first time you hear it: the thorny devil drinks through its skin.

Not through its mouth. Not by finding a puddle and lowering its head to drink. It stands on damp sand — or presses its body against a wet leaf, or simply allows morning dew to settle on its scales — and the water travels, entirely on its own, from the outside of the lizard’s body to its mouth. No pumping. No muscular effort. The water moves uphill, against gravity, through a network of microscopic channels between the lizard’s scales, drawn forward by capillary action alone.

It is one of the most elegant pieces of biological engineering in the animal kingdom, and it exists because the thorny devil (Moloch horridus) lives in one of the harshest environments on earth — the arid desert scrublands of central and western Australia, where rainfall is measured in millimetres per year and surface water is essentially nonexistent for months at a time.

Built Like Armour, Designed Like a Machine

The thorny devil is small — adults reach about 20 centimetres in length and weigh less than 100 grams. But its appearance is extraordinary. Every surface of its body is covered in conical spines, ranging from small thorns along its flanks to large, curved spikes on its head and back. It looks, at first glance, like something that crawled out of a fantasy novel — a miniature dragon, armoured and ancient-looking, moving with a slow, rocking gait across the red sand.

The spines serve an obvious defensive purpose. A thorny devil is extremely difficult to swallow — the spines catch in a predator’s throat, making the lizard a deeply unpleasant meal for any snake or bird of prey that attempts it. But the spines are also the key to the lizard’s water collection system.

Each spine is not smooth. Under magnification, the surface of a thorny devil’s spine is covered in tiny hygroscopic grooves — channels so small they are invisible to the naked eye. These grooves connect to a network of similarly microscopic channels that run between the scales across the lizard’s entire body surface, all of them converging toward the corners of the mouth.

When moisture contacts any part of the lizard’s skin — whether from dew, rain, wet sand, or a damp plant surface — it is immediately drawn into these channels by capillary action. The water then travels through the network toward the mouth, where the lizard makes small gulping movements to draw it in. The entire outer surface of the animal functions as a water collection and transport system, with the spines acting as both the collection points and the structural framework for the channels between them.

Researchers studying water scarcity and passive water collection have examined the thorny devil’s skin structure in detail, and several biomimetic engineering projects — designs for surfaces that collect and transport water without any mechanical input — have drawn directly on what the thorny devil evolved over millions of years in the Australian desert.

The False Head

The water collection system is remarkable. But the thorny devil has a second adaptation that is, in its own way, equally impressive.

On the back of its neck, the thorny devil has a large, rounded hump covered in spines. This hump is not a storage organ — it does not contain fat or water reserves. It is a decoy. When threatened, the thorny devil tucks its real head down between its front legs, presenting the false head hump to the predator instead.

The effect is disorienting. A snake or bird of prey approaching what it believes is the lizard’s head suddenly finds itself confronted with a spiny lump that offers no obvious point of attack — no eyes to target, no vulnerable neck to strike. The real head, meanwhile, is tucked safely away, protected by the lizard’s armoured back.

It is a deception built entirely from anatomy — no behaviour required beyond the simple act of lowering the head. The false head does not move, does not react, does not do anything except exist in the right place to confuse a predator at the critical moment.

100 Ants at a Time

The thorny devil’s diet is as specialised as everything else about it. It eats ants — almost exclusively — and it eats them one at a time, with a precise, rapid tongue strike, at a rate of up to 45 ants per minute. A single thorny devil may consume between 600 and 3,000 ants in a single feeding session, sitting motionless beside an ant trail and picking them off as they pass.

This dietary specialisation is unusual among lizards, most of which are opportunistic feeders. The thorny devil’s commitment to a single prey type means it is entirely dependent on the health of ant populations in its habitat — a vulnerability that becomes significant as land clearing and habitat degradation alter the composition of ant communities across the Australian interior.

It is also, practically speaking, a very slow way to eat. The thorny devil spends a significant portion of its active hours simply sitting beside ant trails, waiting. Its slow, rocking walk — which mimics the movement of a dead leaf in the wind, providing camouflage as it moves between feeding sites — means it covers very little ground in a day. Its entire existence is calibrated for minimal energy expenditure in an environment where energy, like water, is a resource that cannot be wasted.

An Ancient Design

The thorny devil has been in Australia for a very long time. Its closest living relative is the horned lizard of North America — a superficially similar animal that evolved the same spiny armour and ant-eating lifestyle independently, on a different continent, through a process called convergent evolution. Two lineages, separated by oceans and millions of years, arrived at almost identical solutions to similar environmental pressures.

This convergence is a testament to how effective the thorny devil’s design is. The spines, the water channels, the false head, the specialised diet — these are not quirks. They are solutions, refined over geological time, to the specific and brutal demands of desert survival.

The Australian outback is not a forgiving place. The thorny devil has been living there, unchanged in its essential design, since long before humans arrived on the continent. It will, in all likelihood, still be there long after we have finished marvelling at it.

Would you rather drink through your skin or go without water for weeks like a camel? Tell us which desert survival trick you’d choose.