Discover the fascinating world of one of Earth’s most ancient and unique mammals—a creature so bizarre, scientists once thought specimens were a hoax.

If you’ve never heard of an echidna (pronounced ih-KID-na), you’re in for a treat. This small, spiny creature is one of the most remarkable animals on the planet—and one of the least understood.

Native to Australia and New Guinea, the echidna is a monotreme, meaning it belongs to the only group of mammals on Earth that lays eggs. Yes, you read that right: a warm-blooded, fur-covered mammal that hatches from an egg.

Sometimes called the “spiny anteater” (though it’s not actually related to anteaters), the echidna has survived for millions of years with virtually no evolutionary changes. In many ways, it’s a living window into the ancient past of mammalian life on Earth.

There are 4 recognized species of echidna in the world:

• Short-beaked Echidna (Tachyglossus aculeatus) — The most common and well-known species, found across Australia and parts of New Guinea. This is the echidna most people picture when they hear the name.

• Sir David’s Long-beaked Echidna (Zaglossus attenboroughi) — Named after the legendary naturalist Sir David Attenborough, this critically endangered species is found only in the Cyclops Mountains of Papua New Guinea. It is so rare that it was considered possibly extinct until a camera trap photographed one in 2023.

• Eastern Long-beaked Echidna (Zaglossus bartoni) — Found in the highlands of New Guinea, this species is larger than the short-beaked variety and is considered vulnerable due to habitat loss and hunting.

• Western Long-beaked Echidna (Zaglossus bruijnii) — The largest of all echidna species, this critically endangered animal is native to western New Guinea and faces severe threats from deforestation and poaching.

The echidna’s appearance is instantly recognizable—and it’s unlike almost anything else in nature. Its back and sides are covered in sharp, hollow spines made of keratin (the same protein as human fingernails), which can grow up to 5 to 6 centimeters long. These spines are interspersed with coarse, dark fur that provides insulation in cooler climates.

Beneath those impressive spines is a compact, powerful body built for digging. The echidna’s limbs are short and muscular, ending in broad, strong claws perfectly designed for tearing apart soil, logs, and termite mounds.

Its face features a distinctive long, leathery snout—short in the Australian species and considerably longer in New Guinean species—which functions as both a nose and a feeding tool. The echidna has no teeth whatsoever. Instead, it uses a long, sticky tongue to catch prey.

Short-beaked echidnas typically weigh between 2 and 7 kilograms and measure about 30 to 45 centimeters in length, making them roughly the size of a small rabbit or large hedgehog.

Echidnas are insectivores, feeding primarily on ants, termites, earthworms, and other small invertebrates. Their method of hunting is both efficient and fascinating.

Using their sensitive snout, echidnas detect prey through a combination of smell and electroreception—the ability to sense the tiny electrical fields generated by living organisms. This makes them exceptional hunters even in complete darkness or underground.

Once prey is detected, the echidna uses its powerful claws to rip open ant mounds, rotting logs, or soil. It then extends its long, sticky tongue—which can reach up to 18 centimeters in length and flick in and out up to 100 times per minute—to lap up insects by the dozens.

If there’s one thing that makes echidnas truly unforgettable, it’s how they reproduce. As monotremes, they’re among the only mammals on Earth that lay eggs—a trait shared with just one other animal, the platypus.

Here’s how it works:

After mating, the female develops a single leathery egg inside her body. About 22 days later, she transfers it into a temporary pouch on her abdomen. The egg is tiny—about the size of a grape. Roughly 10 days after that, it hatches into a tiny, underdeveloped baby called a puggle—arguably one of the most charming names in the animal kingdom.

The puggle is blind, hairless, and no bigger than a jellybean. It feeds by lapping up milk that seeps through specialized patches of skin inside the mother’s pouch—echidnas don’t have nipples, but they still nurse their young.

It stays safely tucked inside the pouch for about 6 to 8 weeks, growing quickly until its developing spines make things a little too uncomfortable for mom.

At that point, she places the puggle in a burrow and returns every few days to nurse it. This continues until the young echidna is fully weaned at around 12 months old.

Despite being slow-moving animals, echidnas are surprisingly difficult to harm. Their primary defense mechanism is simple and remarkably effective: they curl into a tight ball, tucking their soft undersides away and presenting nothing but a sphere of sharp spines to any would-be predator.

On soft ground, echidnas take this a step further by rapidly digging straight down, leaving only their spiny back exposed. Within seconds, they can partially bury themselves, making it nearly impossible for most predators to dislodge them.

This strategy is effective against dingoes, goannas, and birds of prey. However, introduced predators such as foxes, feral cats, and domestic dogs—which behave differently from native Australian wildlife—have made survival more challenging for echidnas in many parts of their range.

Don’t let the blank stare fool you. Echidnas are surprisingly intelligent animals. Research has shown that, relative to body size, echidnas have one of the largest prefrontal cortexes of any mammal—the brain region associated with planning, problem-solving, and complex behavior.

Studies have demonstrated that echidnas can navigate mazes, remember solutions, and adapt to novel challenges with a degree of cognitive flexibility that rivals some primates. Scientists believe this high intelligence may have evolved partly because monotremes had to develop complex survival strategies without the benefit of the sophisticated social structures that helped other mammals thrive.

Echidnas are masters of surviving tough conditions. During extreme heat or cold, they enter a state of torpor—a type of deep, energy-conserving sleep similar to hibernation—in which their body temperature drops dramatically and their metabolic rate slows to a crawl.

In cold climates, echidnas can remain in torpor for weeks at a time. Interestingly, research has found that echidnas experience REM sleep—the sleep phase associated with dreaming—most intensely when their body temperature is moderate, suggesting that the capacity for dreaming may be far more ancient than previously thought.

The short-beaked echidna is one of Australia’s most adaptable native mammals. It can be found in an extraordinary range of environments, including:

• Dense rainforests along the eastern coast
• Dry scrubland and desert regions of the interior
• Alpine meadows and snow-covered mountain slopes in the southeast
• Urban parks, farmland, and suburban gardens

This adaptability is one reason the short-beaked echidna is not currently considered endangered, unlike its long-beaked relatives in New Guinea, which face serious conservation threats.

The short-beaked echidna is listed as Least Concern on the IUCN Red List, meaning it is not currently at risk of extinction. However, that doesn’t mean it faces no threats. Key challenges include:

• Habitat loss — Urban sprawl, land clearing for agriculture, and road construction all reduce available echidna habitat and fragment populations.

• Road mortality — Echidnas are slow movers and are frequently killed by vehicles, particularly during the breeding season when they travel greater distances searching for mates.

• Introduced predators — Foxes, cats, and dogs kill echidnas, particularly juveniles and puggles that lack the experience to defend themselves.

• Climate change — Increasing temperatures and more frequent extreme weather events affect the availability of food and the suitability of hibernation conditions.

All 3 long-beaked echidna species are classified as Critically Endangered or Vulnerable, with habitat destruction and hunting posing severe threats to their survival in New Guinea.

• Echidnas have four-headed penises—one of the most unusual reproductive anatomies in the animal kingdom.
• They can live for up to 50 years in captivity, making them one of the longest lived small mammals on Earth.
• Echidnas cannot sweat or pant to cool down. They rely on shade, burrows, and torpor to regulate their temperature.
• The echidna appears on the Australian 5 cent coin, a nod to its status as a national icon.
• Echidnas have no external ears—just small openings hidden beneath their fur and spines.
• Despite their slow, lumbering gait, echidnas are capable swimmers and will readily cross streams and ponds.

If you’re visiting Australia and hoping to encounter an echidna in its natural habitat, here are a few tips:

• When to look: Echidnas are most active in the early morning and late afternoon, avoiding the heat of the midday sun. In cooler southern states, they may be active throughout the day.

• Where to look: Echidnas love areas with loose soil, rotting logs, and abundant ant and termite activity. National parks, bushland reserves, and even well-vegetated suburban areas can all be good spots.

• What to do if you find one: Observe from a respectful distance and never try to pick one up or disturb it. If startled, an echidna will curl into a ball or begin digging—simply wait patiently and it will eventually resume its activities.

The echidna is far more than just a quirky curiosity. As a monotreme, it represents an ancient and extraordinary branch of the mammalian family tree—a living glimpse into what early mammals may have been like long before the diversification of species that produced the world we know today.

Research on echidnas has already transformed our understanding of mammalian evolution, brain development, sleep, and reproduction—and there’s still so much left to learn.

Beyond its scientific importance, the echidna stands as a symbol of resilience. It has endured ice ages, mass extinctions, continental shifts, and the rise of humans. In a rapidly changing world, that kind of resilience isn’t just fascinating—it’s something worth recognizing, celebrating, and protecting.