5 Amazing Facts About the Sloth

Slow and always smiling, here are 5 amazing facts about sloths!

Sep 28, 2023By Lauren Rey
facts about the sloth

Slow and steady is a way of life for the sloth. These gentle creatures move ever so slowly and carefully throughout the rainforests of Central and South America. Leisurely by nature, the sloth’s slowness is just one way this amazing animal is built to survive. Here’s a look at some other fascinating facts about these tired little tree-dwellers!

5. Sloths Are the World’s Slowest Mammals

sloth climbing
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Sloths are famously known as the world’s slowest mammals, but not many people know why. A sloth's slow nature is actually a survival mechanism. While ancient ground sloths ate various plants and roamed vast lands, today’s arboreal sloth evolved for life in the trees. This meant surviving on foliage. This leaf-heavy diet contained very little nutrition, so sloths adapted to make the most out of every meal.

Modern-day sloths have an extremely slow metabolism and digestion rate. It can take up to a full month for a sloth to digest just one meal. Their metabolic rate is also around 40% slower than that of similar-sized mammals, and they have a lower internal body temperature. All of these factors add up to produce one energy-saving, slow-moving sloth!

4. Sloths Spend 90% of Their Time Upside Down

upside down sloth
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Sloths are highly adapted to life among the trees, in fact, they spend 90% of their time hanging upside down! While it’s apparent from the outside that sloths were built for this, a sloth’s internal organs and circulatory system are also built for life upside down.

While most other mammals would have a hard time breathing if upside down for too long, sloths have special adhesions anchoring their abdominal organs to their ribs. This prevents their organs from putting pressure on their lungs so they can breathe normally while hanging upside down.

Sloths also have a specialized circulatory system to ensure blood keeps flowing and doesn’t pool in their heads while upside down. They can also eat while upside down thanks to their unique looped esophagus, which prevents the food from falling back out. A feat that would be difficult for most other mammals with a linear esophagus. Sloths have quite an array of unique anatomical features to assist them in their upside-down life!

3. Sloths Were Not Made for Walking

sloth crossing street
Photo Credit: Getty Images/Canva

Sloths are arboreal, or tree-dwelling animals. Their bodies were made for climbing and hanging, not walking. They have long limbs and hook-like claws that help them glide across the rainforest canopy where they spend almost their entire life. Sloths rarely leave the safety of their trees except to relieve themselves, which, thanks to their slow-moving digestion, they only need to do about once per week.

Occasionally, sloths will find themselves in the unfortunate situation of having to move on the ground, usually to cross a street. They will do this by slowly and awkwardly dragging themselves across the pavement. Unlike monkeys and other arboreal animals, sloths cannot leap or run when needed, so they are at the mercy of traffic. The Sloth Conservation Foundation works tirelessly to install sloth crossings on busy rainforest roads in Central America. These crossings consist of ropes that go across the canopy, above roads, to help sloths and other arboreal animals safely cross the street.

2. Sloths Have an Entire Ecosystem Living in Their Fur

algae covered sloth
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The sloth is truly one with its environment, blending seamlessly into the rainforest canopy, and providing a haven for different species of algae, fungi, and insects. In fact, sloths have entire mini ecosystems living right on their backs!

The organisms that take shelter in a sloth’s fur also offer the sloth some amazing benefits. Green algae, which grows on their fur and is fertilized by insects, gives the sloth unbeatable camouflage. Predators scanning the treeline for prey will have a hard time identifying it due to the algae, which gives the sloth a green coloring. The algae also provide the sloth with a mobile snack. Yes, sloths will eat the algae growing out of their fur. A fascinating, albeit unsavory, symbiotic relationship!

1. Sloths Are Always Smiling, but They Are Not Always Happy

sloth smiling
Photo Credit: Getty Images/Canva

While sloths may always look happy, looks can be deceiving. Sloths have a permanent “smile” due to their unique facial structures. Unfortunately, they are one of the most commonly used animals in captive animal tourism, often being posed for photos with tourists. Their docile, slow nature coupled with their “smile” leads many to believe the sloth is enjoying interaction, but the truth is this is incredibly stressful for them.

The Sloth Conservation Foundation strongly discourages people from partaking in “sloth selfies” or any sort of sloth-handling attraction. They also strive to educate the public about sloth behavior and that these gentle creatures are actually quite timid and need their space. It’s important to remember that a sloth’s smile doesn't mean they are happy!

Lauren Rey
By Lauren Rey

A lover of all animals, Lauren’s background is in the veterinary world, but she is now a content writer on travel, wildlife, and all things pets! She’s based in Florida, but when not writing, she’s usually plotting out a new road trip route with her partner-in-crime. Pickles is a mixed-breed rescue dog that loves hiking, road trips, and Starbucks just as much as her mom does!