Scales and Ant Eaters
How Different Animals Solved the Same Problem
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Many people, even here in South Africa, see our Let's Live pangolin logo and say, “Is that an armadillo?”
* Temminck's Ground Pangolin (left) and three-banded armadillo (right) curled up into a defensive ball.
Fair enough. Both are shy, mostly nocturnal mammals with armoured bodies, long claws, and a knack for raiding ant and termite nests. But here’s the twist: pangolins and armadillos are not close relatives at all.
Pangolins belong to their very own order, Pholidota. Their closest living relatives are actually the Carnivora (the group that includes dogs and cats) and the Euungulata ( horses, antelope, and even rhinos). In fact, a pangolin shares a more recent common ancestor with you, a primate, than it does with any of the other ant-eating mammals that you might confuse it with at first glance (anteaters, armadillos, aardvarks, numbats, or echidnas).
So why do so many mammals, scattered across the Americas, Africa, Asia and Australia - separated by thousands of kilometres and tens of millions of years of evolution - end up looking and behaving so similarly?
The answer is convergent evolution: when unrelated species independently evolve similar traits because they’re solving the same ecological problem.
And the problem? Ants and termites.
There are an estimated 20 quadrillion ants on Earth. Together, ants and termites outweigh all the world’s mammal and bird species combined. To a hungry animal, that’s an endless, sustainable buffet. No wonder evolution has nudged more than 200 mammal species into eating them at least some of the time - but only around 20 species have gone all-in, specialising almost entirely on ants and termites.
Animals that specialise in feeding primarily on ants and termites are called myrmecophages. Some go even further and focus almost entirely on termites, termitophagy. Others just dip into the buffet: ants and termites are on the menu, but so are plenty of other insects. Those are generalist insectivores.
Let’s meet the cast. Starting with our scaly star.
Pangolins (Africa & Asia)
Pangolins are the world’s only mammals covered in true scales - tough keratin plates that grow continuously throughout their lives, like overlapping fingernails. Pangolins are completely toothless, but that’s no problem if your prey is soft-bodied insects. A pangolin’s long, sticky tongue (which can be nearly as long as its body) is anchored deep in the chest cavity, behind the last pair of ribs. It slurps ants and termites straight into a muscular, gizzard-like stomach lined with keratinous spines that help grind them up. Add massive claws for tearing open rock-hard termite mounds, and you’ve got the perfect ant predator.
But when you spend much of your life with your head buried in a termite mound, you’d better make sure your behind is protected. Pangolins are slow (with a top speed only about 5-10 km/h), so they don’t stand a chance in a foot race with a big cat or hyena. On top of that, by the time a pangolin realises it is in danger, it is too late. So instead of running, they developed scaly armour. When threatened, they can curl up into a tight ball to protect their head and soft underparts, and wait for the predator to get bored, give up and move on.
Contrary to popular belief, an animal doesn’t “decide” to grow armour because it needs protection. Evolution doesn’t work by conscious choice. Each individual animal is born with a slightly different mix of genes from its parents, plus a few random mutations. Some mutations result in changes that are harmful, some helpful, but most don’t matter much at all.
Early ancestors of pangolins (“proto-pangolins”) that lived long before the group split into what would eventually give rise to today’s pangolins, dogs and cats, were covered in hair (like most mammals) and not scales. But over many generations, the individuals with thicker, tougher, more protective hairs had a better chance of surviving attacks and living long enough to reproduce. Their offspring inherited those traits, and over millions of years these tiny advantages piled up, leading to the species developing thicker and thicker hair. Eventually, those modified hairs lead to the development of hardened keratin scales.
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Lineage: Pholidota (branched off from a common ancestor that they share with dogs, cats and even horses)
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Diet: Myrmecophagy (ants & termites)
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Key adaptations: Toothless jaws, a long sticky tongue anchored near the hip and the last pair of ribs, a gizzard-like stomach to grind insects, and powerful digging claws
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Armour: The only mammals that is covered from head to tail in keratin scales. Curls into a tight ball when threatened
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Range: 8 species worldwide - 4 in Africa, 4 in Asia
Armadillos (Americas)
If pangolins are Africa and Asia’s scaly anteaters, then armadillos are their armoured counterparts in the Americas. At a glance, they look like they were cut from the same evolutionary cloth: low to the ground, armoured backs, sticky tongues, long claws, and a taste for ants and termites. But under the surface, it’s a completely different story.
Armadillos belong to a group of mammals called Xenarthrans, alongside sloths and anteaters. Instead of keratin scales, their armour is made of bony scutes. Tiny bone plates called osteoderms form a shell under the skin, which is then covered by a tough layer of keratin. From a distance, it can look “scaly”, but structurally it’s the opposite of a pangolin: pangolin scales grow like super-charged fingernails; armadillo armour grows as part of the skeleton.
They’re also nowhere near as specialised in their diet. While pangolins are true myrmecophages, armadillos are more opportunistic foragers. Most species are generalist insectivores or omnivores, happily eating ants, termites, beetles, grubs, worms, fruit, roots, and even carrion when they find it. Some species have moderately long, sticky tongues to help scoop up insects, but they’ve held onto something pangolins gave up long ago: teeth. Armadillos still chew.
Like pangolins, armadillos are excellent diggers. Their strong forelimbs and long claws let them tear into insect nests and excavate burrows where they shelter from predators and extreme temperatures. Three-banded armadillos can also curl into a tight ball that looks strikingly like a pangolin’s defensive posture - another beautiful example of convergent evolution.
The same problem, how to eat armoured insects and not get eaten yourself, resulted in an evolutionarily similar toolkit.
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Lineage: Order Cingulata, part of the Xenarthran group with sloths and anteaters
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Diet: General insectivore/omnivore (ants, termites, beetles, grubs, fruit, roots, other small prey)
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Key adaptations: Strong digging claws; some have sticky tongues.
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Armour: Bony osteoderms under the skin, covered in keratin scutes that look “scaly” but are actually a bone-based
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Defence: Many species rely on burrows and fleeing to escape danger, but a few can roll into a ball, echoing the pangolin’s strategy
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Range: 21 species, found from the southern United States through Central America and deep into South America
Anteaters (South America)
The true ant-eaters of South America take the name literally. Yet despite their similar diet and lifestyle to pangolins and armadillos, their closest living relatives are sloths.
All anteaters are true myrmecophages, evolved almost entirely around one mission: extracting ants and termites. Their bodies are tuned to this niche. An elongated snout houses a sticky tongue that can stretch up to 60 centimetres, flicking in and out up to 150 times a minute to lap up insects with astonishing speed. Like pangolins, anteaters have no teeth, relying instead on a muscular, grinding stomach to break down their prey.
Their massive claws are formidable tools for tearing open termite mounds and anthills, but they also make anteaters slow, awkward walkers. They tread on their knuckles to avoid stabbing their own palms or dulling their claws on the ground. Lacking hard, scaly defences, anteaters go on the offensive when threatened: those same claws become powerful weapons. A well-aimed swipe from a giant anteater can fend off even large predators, like jaguars.
Four species roam Central and South America, from the tiny silky anteater in the canopy to the two and three-toed tamanduas, and the largest of all the giant anteater, which can reach over two metres from nose to tail. They share the same evolutionary solution to the “ant problem,” but arrived there via a completely different path from pangolins or armadillos.
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Lineage: Order Pilosa (close cousins of sloths)
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Specialisation: Myrmecophagy (ants & termites)
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Key adaptations: Long claws, an elongated snout, a sticky tongue up to 60cm, no teeth and a stomach that grinds its prey
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Range: 4 species, found in Central and South America
Aardvark (Africa)
Africa’s homegrown ant and termite specialist is probably the strangest-looking animal on our list of strange-looking animals. An aardvark looks like a mash-up of several different species: a pig-like snout and body, rabbit ears, an anteater's elongated face, an arched back, stubby legs with bear-worthy claws, and a thick, kangaroo-ish tail. But aardvarks aren’t closely related to any of these animals or the other ant-eaters on this list. They’re the lone survivors of the order Tubulidentata, within the African super-group Afrotheria. Among the ant-eating cast, the aardvark lineage is the only one that originated in Africa.
Aardvarks are elusive, nocturnal diggers. Shovel-like claws on powerful forelimbs rip open termite mounds to reach their prey. The burrows they excavate can span several meters underground, and they move house often, leaving behind vital shelters for many other species (warthogs, porcupines, hyenas, jackals and even pangolins).
A highly sensitive, flexible snout and an exceptional sense of smell pinpoint underground nests. Once a colony is located, they use their long, sticky tongue to whip up ants and termites at speed. Thick skin and the ability to close the nostrils help against biting insects and dust.
Unlike pangolins and anteaters, aardvarks do have teeth, but only at the back of the jaw. But they’re unlike any other mammal. Their teeth are tubular, enamel-less, hexagonal columns that grow continuously. Although they have these teeth, their food is seldom chewed and is rather churned in a muscular stomach. The reason why the aardvark retained these teeth, despite not needing them to chew ants, is that they also eat the fruit of the cucumis humifructus for its water content. The common name for this fruit is the 'aardvark cucumber' - named this due to the plant's complete reliance on the aardvark to dig up its fruit, which ripens deep below the ground, and propagate the seeds through their faeces, which the animal buries.
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Lineage: Order Tubulidentata (within Afrotheria; distant relatives include elephants, hyraxes, tenrecs, golden moles)
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Diet: Myrmecophagy (ants & termites) and aardvark cucumbers
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Key adaptations: Snout with keen smell, long sticky tongue, powerful digging claws
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Defence/behaviour: While they are tough animals, they do not have armour to speak of, and instead rely on a rapid retreat to their burrows
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Range: Widespread across sub-Saharan Africa
Aardwolf (Africa)
The aardwolf is part of the hyena family, but unlike its bone-crunching cousins, this gentle insectivore feeds almost exclusively on termites. Throughout this series we’ve seen examples of convergent evolution (unrelated species evolving similar traits to solve the same problem). The aardwolf, however, is a rare case of divergent evolution: a predator lineage that took a completely different turn.
Aardwolves have catlike teeth that aren’t built for chewing termites, so instead they rely on a long, sticky tongue to lap them up by the hundreds, sometimes consuming over 300,000 termites in a single night. Their slender muzzle and sensitive hearing help them detect termite activity underground, while their lightweight frame lets them forage quietly under the cover of darkness.
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Lineage: Family Hyaenidae
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Diet: Termitophagy (almost exclusively termites)
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Key adaptations: Catlike teeth not used for chewing, long sticky tongue, delicate snout and keen hearing for termite detection
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Range: Eastern and Southern Africa
Echidna (Australia)
Australia’s spiny ant-eater is an ancient oddity: an egg-laying mammal that solves the ant-and-termite problem with its own unique toolkit. Echidnas wear spiny armour made of modified hairs, use digging claws to break open nests, and have a long, sticky tongue that they flick from a narrow snout to lap up insects. They have no teeth, and food is mashed against abrasive pads on the roof of their mouth.
Echidna's keratin spines are functionally similar to those of hedgehogs and porcupines, but they evolved completely independently - another striking example of convergent evolution. Echidnas use them mainly for defence, and when threatened, they curl up, leaving only their spines exposed.
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Lineage: Monotremes (egg-laying mammals; relatives include the platypus)
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Diet: Myrmecophagy (ants & termites)
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Key adaptations: Spiny armour, long sticky tongue, no teeth (abrasive, spiky mouth pads), powerful digging claws
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Range: The short-beaked echidna is widespread across Australia and Tasmania. The three species of Long-beaked echidnas are found in New Guinea
Numbat (Australia)
Among the world’s termite specialists, the numbat stands out as the only marsupial devoted to the cause. This small, striped creature from Western Australia spends its days - literally, since it’s diurnal - wandering the bush with a slender snout and a long, sticky tongue in search of termites. With sharp claws for prying open soil and rotting wood, it can devour up to 20,000 termites a day.
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Lineage: Marsupial. Sole member of Myremecobiidae, close kin to quolls and the Tasmanian devil
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Diet: Termitophagy (termites only)
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Key adaptations: Diurnal foraging, long sticky tongue, sharp claws, slender snout, delicate non-chewing teeth
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Range: Now limited to southwestern Australia, with reintroduction programs expanding their range
Why These Animals Matter
Pangolins may look like armadillos. Aardvarks may look like anteaters. But they’re all distant, separated by vast evolutionary gulfs.
What binds them isn’t ancestry - it’s ants and termites. Over tens of millions of years, nature has evoloved similar solutions again and again to get at the trillions of insects underfoot. That’s convergent evolution in action.
There are a few other traits that unite this odd club of ant-eaters.
Almost all of them are solitary. Ants and termites may be abundant, but they’re spread out across the landscape. Most of these animals have large territories and walk vast distances in search of food. A single mound or nest can hold millions of insects, but after a predator “attack”, it takes time for the colony to recover. To avoid wiping out their own food source, these predators tend to live alone. Reducing competition makes each meal go further, for longer.
Most of them are also nocturnal, emerging under the cover of darkness when temperatures drop and insects are easiest to find. Even the exceptions - like the diurnal numbat - still follow the rhythms of their prey.
They also tend to have low reproductive rates, usually raising just one baby at a time, because specialised diets limit how much energy they can spare.
Each of these animals is a keystone species in their respective habitat, and taking them out of the picture would result in many other species struggling to survive.
They keep insect numbers in check, helping to protect the plants and trees that so many animals depend on.
They are also master diggers, turning soil and opening up hard ground, in their search for food. This lets water and air reach deep underground, helping new plants grow and creating safe homes for smaller creatures.
There’s a downside to all this specialisation.
Because they are so finely tuned to one narrow way of life, many of these species are now vulnerable, threatened, or endangered. Slow breeding, reliance on specific habitats and prey, and a lack of fear of natural predators leave them unsuited to rapid habitat loss, climate change, and hunting by humans. The same traits that make them such elegant solutions to the “ant problem” now make them fragile in a world changing faster than evolution can keep up.
“Take away the animal that shapes the soil, and the land forgets how to breathe.”
To understand a pangolin, we first need to understand ants. If you want to read more about what we have learnt from observing the fascinating predator/prey relationship between ants and pangolins, while observing them out in the field, you can read this article next: Walking Beside a Pangolin