What Do Echidnas Eat? Ants, Termites and Sticky Tongues

What does a short-beaked echidna eat?

The short-beaked echidna is an insectivore, a mammal that lives mainly on insects. Its main foods are:

• Ants, including the eggs, larvae, pupae and winged adults inside the nest
• Termites, taken from mounds, underground tunnels and rotting wood
• Beetle larvae, especially the fat white grubs of scarab beetles in the soil
• Moth larvae and other insect grubs
• Earthworms and other small invertebrates, as long as they are small enough to fit through the tiny mouth

The mouth at the tip of the snout opens only about 5 mm (0.2 in) wide, so the echidna cannot tackle large prey. Bigger beetle grubs are squashed inside the snout as they are drawn in.

Echidnas are also choosy. They avoid some ants and termites that defend themselves with strong chemicals, including certain termites of the family Rhinotermitidae, and they prefer the soft, nutritious young stages in the nest over tough adult workers.

How diet changes with region and season

What an echidna eats depends on where it lives. In dry inland Australia, termites are plentiful and usually make up the bulk of the diet. Termites are also preferred where available, because their soft bodies have less indigestible outer skeleton than ants.

In wetter forests and farmland in the east and south, ants and scarab beetle larvae are more important. In one study in the New England region of New South Wales, beetle larvae made up about 37% of the food eaten.

The season matters too. Echidnas feed most intensively in late winter and spring, after the breeding season and their winter hibernation have used up their fat reserves. At that time of year, ant nests are rich in fat-filled winged ants that are about to fly, and echidnas often target them.

How do echidnas find their food?

An echidna forages by wandering slowly with its snout close to the ground, poking it into leaf litter, soil and cracks in logs. Smell appears to be its most important sense for finding prey.

The snout tip also carries touch receptors and a few hundred electroreceptors, which can pick up the weak electric fields produced by living animals. This sense is far less developed than in its relative, the platypus, which hunts underwater with tens of thousands of electroreceptors; see how platypuses find food. Echidnas also hear low-frequency sounds well, which may help them detect insects moving underground.

Eyesight is much less important. Blind echidnas have been found living healthily in the wild, which shows that they can feed using smell and touch alone.

Once it has found a nest, the echidna rips into it with the broad, flattened claws on its front feet. It can break open hard termite mounds, peel bark from logs and dig rapidly into soil.

The sticky tongue and a mouth without teeth

The echidna’s tongue is its only tool for catching prey. The scientific name of the short-beaked echidna, Tachyglossus, means “fast tongue.” The tongue can reach up to about 18 cm (7 in) beyond the snout and moves in and out roughly 100 times a minute.

Sticky mucus coats the tongue so that ants and termites cling to it. Blood rushing into the tongue stiffens it, allowing it to probe deep into wood and soil.

Echidnas have no teeth. Instead, rows of hard, backward-pointing spines made of keratin line the roof of the mouth. When the tongue pulls back, the prey is scraped off and ground between these spines and horny pads at the back of the tongue.

Digestion is unusual too. The echidna’s stomach has almost no acid and works mainly as a grinding chamber, mixing crushed insects with the soil that is swallowed along with them. Most digestion happens in the long small intestine, and the soil and insect skeletons pass out in the droppings, which are often packed with ant remains.

How much do echidnas eat?

Echidnas can eat surprisingly fast. A 3 kg (6.6 lb) echidna has been recorded eating around 200 g (7 oz) of termites in only ten minutes. In one laboratory study, an echidna ate about 147 g (5.2 oz) of termites a day, most of it water.

That water is important. Echidnas cannot sweat or pant, and they lose water through the skin and breathing. Juicy termites, together with drinking water and licking dew from plants when available, keep them going even in dry country.

Because their metabolism is very slow, about a third of that of a typical placental mammal of similar size, echidnas need less food than you might expect for an animal that is almost always foraging.

How echidnas compare with other ant-eaters

Several unrelated mammals around the world eat ants and termites and have ended up with similar tools: a long snout, a long sticky tongue, strong digging claws and few or no teeth. This is a classic example of convergent evolution, where different animals evolve similar features because they live in a similar way.

Read more in how anteaters eat ants and what aardvarks eat. The echidna is the only one of these that lays eggs.