How Do Anteaters Eat Ants? Tongue, Claws and No Teeth

Step by step: how an anteater feeds

The giant anteater is the best-studied member of the family, and its feeding routine is a model of efficiency.

1. Finding a nest by smell. Anteaters have weak eyesight but an excellent nose, often described as about 40 times more sensitive than a human’s. They walk slowly with the snout close to the ground, sniffing out ant nests and termite mounds.
2. Opening it up. The anteater digs into the soil or rips a hole in the hard wall of a termite mound with the large claws on its front feet. The middle claw, about 10 cm (4 in) long, does most of the work in a hooking and pulling motion.
3. Feeding with the tongue. It pushes its narrow snout into the hole and shoots the tongue in and out very fast. Ants, termites, eggs and larvae stick to it and are pulled into the mouth.
4. Swallowing and moving on. After about a minute, sometimes less, the anteater stops and walks to the next nest.

The tongue: long, thin and sticky

The giant anteater’s tongue is about 60 cm (24 in) long, but only about 1 cm (0.4 in) wide. Around 45 cm (18 in) of it can be pushed out of the mouth. It is covered in tiny backward-pointing spines and coated with thick, sticky saliva from very large salivary glands, so insects cannot easily escape.

What makes the tongue so fast is how it is attached. It is not anchored in the mouth or throat like ours, but far back on the breastbone, by a special muscle. That long “launch track” lets the tongue move in and out around two to three times every second. Because the mouth is a tiny opening at the tip of a tube, the tongue can only go straight forward and back, so the anteater aims with its whole head.

No teeth: how do anteaters chew?

Anteaters do not chew at all. They have no teeth, and the jaw barely opens. Instead, the two halves of the lower jaw roll slightly to open the small mouth just wide enough for the tongue.

The tongue presses insects against hard ridges on the roof of the mouth, crushing them a little. The real grinding happens in the stomach, which has thick muscular walls and hardened folds. Swallowed sand and small grit help mash the hard insect bodies, much like the gizzard of a bird.

Why do anteaters visit so many nests?

An anteater rarely stays more than a minute or so at a nest, and there are good reasons for that:

• Defenders arrive quickly. Soldier ants and termites bite, sting or spray chemicals. Once the soldiers swarm, feeding is no longer worth it.
• Termites retreat. Many termites flee deeper into their mound or into underground tunnels, out of reach.
• Saving the food supply. By taking only a small share from each colony, the anteater leaves it alive to rebuild. It can come back later, a little like a farmer harvesting the same fields again and again.

Studies of wild giant anteaters suggest they may raid up to about 200 nests in a day, eating an estimated 30,000–35,000 insects in total.

Ants or termites?

Despite the name, many anteaters eat as many termites as ants, or more. Which they choose depends on what is common. In seasonally flooded places like Brazil’s Pantanal and the llanos of Venezuela and Colombia, giant anteaters eat mainly ants. In dry grasslands such as Emas National Park in central Brazil, termite mounds are everywhere, and termites dominate the diet. In some areas, anteaters switch between the two with the seasons.

The other anteaters have their own preferences: tamanduas often feed on tree-dwelling ants and termites, while the small silky anteater eats mostly ants found in trees and vines.

How anteaters compare with other ant-eaters

Several unrelated mammals have evolved the same tool kit of a long snout, sticky tongue and digging claws. This is called convergent evolution.

The aardvark is often called an “anteater”, but it is not one. It belongs to a completely different branch of mammals, related to elephants and hyraxes.

Myths and facts

• Myth: anteaters suck up ants through their snouts. Fact: there is no suction. Everything is done with the sticky tongue.
• Myth: anteaters eat only ants. Fact: termites are just as important, and they also take eggs, larvae and some beetle grubs.
• Myth: anteaters wipe out ant colonies. Fact: by feeding only briefly at each nest, they leave most colonies alive.

Anteaters help keep ant and termite numbers in balance across the grasslands and forests where they live. To see what those insects are up against, read how termites build their mounds.