Anteaters: The Sloth’s Closest Relative!

Anteaters: The Sloth’s Closest Relative!

The Xenarthra family

What exactly is a sloth? Are they related to bears? Monkeys? Marsupials? No! Sloths are actually part of a super ancient (and super strange) family of mammals called the xenarthrans (pronounced zen-ar-thrans). In fact, it is thought that this family is one of the oldest groups of mammals left alive today and it includes our beloved sloths as well as anteaters and armadillos. The very name ‘xenarthrans’ literally translates in Greek as “strange joints” and it’s members all share unique articulations in the lower spine.


Xenarthra filogenetic

Among the most famous and ancient of all xenarthrans is probably the Megatherium – an extinct type of Giant Ground Sloth that grew to over 25 feet tall! The first fossils of this animal were originally found by Charles Darwin near Patagonia, Argentina. Did you know that these giant sloths are the reason why we have avocados today? We will dive into the xenarthran family history in more detail in a future post, but for today we want to focus on the sloths closest relative: the anteaters!


What is an Anteater?

The obvious definition would be an animal that eats ants (and termites) – but this would actually apply to all kinds of unrelated animals (such as the aardvarknumbatechidna and pangolin)

Aadvark equidna pangolin
Long snouts are useful for insect eaters!

Scientists originally thought that these different species of ant-eating animals were all directly related because of their similarities: the diet, long tongues, very few teeth, powerful forearms, and tube-like snouts. However, we now know that these species developed their matching features through a fascinating phenomenon called “convergent evolution”.

Convergent evolution is a process where two very different species develop similar traits. The two types of sloth that we see today are also fantastic examples of this – they separated off from each other approximately 30 million years ago and acquired their upside down arboreal lives independently.


Anteater Anatomy

Before we talk about the different types of anteater (yes, there are 4 very different species), lets take a moment to appreciate how wonderfully weird these animals are.

Just look at that face!

Eating insects can be complicated. If you have ever accidentally disturbed an ants nest you will know how unpleasant they can be when aggravated! To avoid this painful situation, an anteater has to act quickly. Thankfully they have ridiculous tongues which makes the whole process much easier. The tongue of an anteater starts at the breastbone and can extend up to two feet long. It is also covered in backward-facing spines and super-sticky saliva for maximum insect collection.

An anteater will break open a nest with it’s powerful sloth-like claws, and then use its long, sticky tongue to lap up as many insects as possible within 60 seconds. They will extend their tongue up to 150 times per minute and can eat up to 30,000 insects per day with this method!

It takes the ants a few moments to realize what is happening, and so by the time they mount a counter attack, the anteater is ready to move on. By only feeding from each nest for a few seconds, the anteater doesn’t completely destroy the colony and so they can always go back for more in the future. The ultimate sustainable diet!



The anteater’s long snout is actually an elongated jaw and they have no teeth at all! Well, they don’t really need them for a diet of ants and termites. They also have poor eyesight – they detect insects with their powerful sense of smell which is up to 40 times that of a human! Poor eyesight and a fantastic sense of smell is a feature shared with the sloths!

When threatened, anteaters will stand on their back feet and open their arms to look bigger. Giant anteaters have been responsible for at least three human deaths, and in all three cases the anteater had been provoked. There’s a lesson to be learned here – don’t poke an angry anteater.


anteater standind meme
You don’t want to pick a fight with an anteater!

The Four Species of Anteaters

1. Giant Anteater (Myrmecophaga tridactyla)

giant anteaters
Giant anteaters, as the name suggests, are the world’s biggest anteater species


Giant is no exaggeration. These guys are the biggest of the family and can reach up to 2 meters (7 ft) in length and weigh up to 50 kg (110 lbs). They are mostly terrestrial and diurnal, and can be found in multiple habitats throughout Central and South America, such as rainforest, grasslands, and savannas.



The scientific name means “ant eater” and “three fingers”, but these animals actually have five digits on the end of each limb (just like the sloths, early explorers apparently couldn’t get the number of fingers/toes right). Because the claws on their front limbs are so large, giant anteaters have to walk on their knuckles (in a similar way to gorillas).


Like sloths, the body temperature of these animals is very low in comparison with other mammals, and their main predators are big cats like jaguars and pumas. Thankfully, however, the giant anteaters are slightly better at defending themselves than a sloth!

This species is listed as Vulnerable by the IUCN as the population is declining. The biggest threats include habitat loss, poaching, wildfires, and road traffic collisions.

2. Silky Anteater (Cyclopes didactylus)

sliky anteaters
Smallest of the four anteater species, the silky anteater, lives in the treetops of south and Central America.


These golden hamster-sized anteaters have to be seen to be believed. Also known as ‘pygmy anteaters’, they measure just 18 inches long from nose to tail and weigh less than 1 lb (400 g). They are the least studied of all the anteaters, probably because they are not only small but also nocturnal and arboreal! Trying to locate a fluffy golden tennis ball at the top of a huge rainforest tree is no easy task – particularly when their favourite tree (the ceiba tree) produces fluffy golden seed pods that look suspiciously like silky anteaters.

Two years ago scientists discovered that there are actually 7 different silky anteater sub-species, although they suspect this might just be the tip of the anteater iceberg. Scientists really don’t know anything about these strange little animals – including how many of them are left in the wild. They are officially listed as “Least Concern” by the IUCN, although the true population status of the 7 subspecies is unknown.



3 & 4. Southern Tamandua (Tamandua tridactyla) and Northern Tamandua (Tamandua mexicana)

Tamandua is a genus of anteaters with two species: the southern tamandua and the northern tamandua.

The last two species are also known as the lesser anteaters (which feels like a slightly insulting name). Both are similar in shape, color, and size: an average length (including tail) of 130 cm and weighing up to 5.5 kg (similar to a fully grown sloth). On the spectrum of anteaters, these guys fall somewhere in the middle between the giant anteater and the tiny silky anteater.

Just like the giant, they have long claws on the front feet that make walking difficult, but like the silky they are also adapted to live, sleep and forage in the canopy of trees. You might wonder how an animal that eats ants finds any food in the trees. Thankfully, these tamanduas also have an appetite for termites, and termites like to build their nests at the tops of trees. The tamanduas strong, prehensile tail provides them with a safety rope while clambering around at the top of the rainforest looking for termites.

As the names suggest, the Southern Tamandua lives in the rainforests of South America, while the Northern Tamandua is found up North in the rainforests of Central America. Both species are listed as “least concern” by the IUCN.


Are anteaters good pets?

Before you ask: no! You should not have one as a pet. These are wild animals that do not enjoy human contact. The giant anteater and the tamanduas can defend themselves perfectly well with those big claws, but the silky is more vulnerable. We know they are wonderfully weird and admittedly very cute, but they need to live in the wild. Even if you found one and took it home, it wouldn’t survive more than a few days in captivity (and then you’d feel pretty horrible).

Most of the anteaters (and sloths) that are sold as pets come from the illegal wildlife trade. This means that poachers in South and Central America have killed a mother to retrieve a baby that is easier to trade.

If you want to get some anteater action (highly recommended), you can always go to see them at a reputable zoo, conservation center or wildlife rescue facility (check out our guide for ethical animal encounters at zoos to make sure you aren’t accidentally supporting animal exploitation). If you get lucky, you might even see one in the wild if you plan a trip to Central or South America!