The Short Answer: No, Sloths Don't Fart
Sloths are one of the only mammals on Earth that do not fart. This is a real, verified scientific fact. It sounds like something someone made up to win a bar trivia round, but it's been confirmed by researchers and published in actual scientific literature. Sloths cannot pass gas.
Now, if you're here because you Googled "do sloths fart" at 2 AM out of genuine curiosity (or to settle an argument), welcome. You're in the right place. Let's get into why these animals defied one of the most universal biological functions in the mammal kingdom.
Why Can't Sloths Fart?
The answer comes down to their digestive system, which is unlike almost any other mammal's.
Sloths are folivores, meaning they eat almost exclusively leaves. Leaves are tough to digest. Most leaf-eating animals have fast-moving guts that process food quickly and produce gas as a byproduct (this is why cows, for example, are champion gas producers). Sloths went the opposite direction.
A sloth's stomach has multiple chambers, similar to a cow's, but the digestion process is extraordinarily slow. It can take up to 30 days for a sloth to fully digest a single meal. During this process, the methane and other gases that would normally become flatulence are instead absorbed through the gut wall and into the bloodstream.
The gas is then processed by the sloth's body and released through respiration (breathing). So technically, sloths do release the gas. They just breathe it out instead of, well, the other way.
The Digestive System Is Wild
Here are a few more facts about sloth digestion that don't get enough attention:
They poop once a week. Sloths climb down from their tree (one of the only times they voluntarily leave), dig a small hole, do their business, cover it up, and climb back. This entire process is genuinely dangerous for them because they're slow and vulnerable on the ground. Scientists still debate why they bother instead of just going from the tree.
Their stomach can hold up to 37% of their body weight in digesting food. That is an absurd ratio. Imagine if a third of your weight was just food being processed. You'd move slowly too.
The bacteria in their gut does most of the work. Sloths rely on symbiotic gut bacteria to break down the cellulose in leaves. Without these bacteria, the leaves would just sit there. The bacteria also produce the methane that gets absorbed instead of expelled.
Two-toed and three-toed sloths digest differently. Three-toed sloths are the slower digesters. Two-toed sloths have a slightly more varied diet (they'll eat fruit, insects, and small lizards occasionally) and digest somewhat faster. Both species share the no-farting trait.
Why This Fact Went Viral
The "sloths don't fart" fact became an internet sensation because it hits the sweet spot of being surprising, slightly gross, and completely verifiable. It's the kind of fact that makes you stop scrolling and say "wait, really?" before immediately telling the person next to you.
It's been featured in books about animal biology, shared on science Twitter hundreds of thousands of times, and turned into the basis for about a million memes. The combination of the world's most relaxed-looking animal and the most relatable bodily function is comedy that writes itself.
The internet's love for sloth content was already well established (slow-motion videos of sloths crossing roads have accumulated billions of views across platforms), and the fart fact added a new dimension to the obsession. It humanized an animal that was already everybody's spirit animal and gave people one more reason to feel a connection.
Other Animals With Interesting Gas Situations
Since we're here, let's cover the rest of the animal flatulence landscape:
Octopuses don't fart either. They don't have the kind of gut bacteria that produces gas. They also don't have the right anatomy for it.
Herring communicate through farts. They release air from their swim bladders through their, uh, posterior, and use the sounds for group coordination at night. Scientists named this "Fast Repetitive Tick" sounds, or FRTs. Yes, real scientists named fish farts "FRTs."
Termites are the biggest farters on Earth relative to their size. They produce more methane per body weight than any other creature, contributing an estimated 1-3% of global methane emissions.
Birds don't fart. They lack the gut bacteria and the anatomical need. Their digestive system processes food so quickly that gas doesn't build up.
The T-Shirt Connection
Look, if you read 800 words about sloth flatulence (or the lack thereof), you're our kind of person. We made a shirt for you.
The Sloth I Farted t-shirt is a biological impossibility on soft Bella+Canvas cotton. It's the shirt for people who appreciate the intersection of animal science and bathroom humor. The sloth on this shirt did what no real sloth can do, and he's not sorry about it.
It's also a conversation starter that's significantly more interesting than most conversation starters. "Actually, sloths can't fart in real life" is a better icebreaker than anything you'll find in a networking book.
