From Twitter to bestseller: a scientific investigation of animal farts
In 2017, quantitative ecologist Dani Rabiotti asked on Twitter if someone had ever wondered if a snake could fart?. Naturally, her investigation on animal flatulence went viral. #doesitfart swiftly gained traction after that. The topic was developed into a book by Rabiotti and her co-author Nick Caruso, which made it to the New York Times Bestseller list in 2018.
In their groundbreaking book Does It Fart?: The Definitive Field Guide to Animal Flatulence, Rabaiotti and Caruso define a fart as “any gas expelled from the end of an animal that is opposite its mouth.”
An animal may fart from its cloaca, which is a combined hole for urination and defecation, or its anus if it has one. A sound is produced when the gas discharge causes the orifice to vibrate against the sphincter muscles of an organism.
Which animals can fart?
According to this article, many animals are capable of farting. Naturally, humans do well, but so do bobcats, dogs, manatees, and hyenas. The toot chorus also includes a good number of unexpected animals. There are enough flatulent creatures to fill a book, as was already mentioned.
Take the herring, for example. The fish can communicate by farting, and it does so consciously. Because herring fart at a frequency too high for predatory fish to detect, their flatulence serves as a code for fish.
Not all farts are made equal, and they can have a variety of uses. As with the herring above, passing gas can be employed to communicate or to ease digestive discomfort. Another way to frighten off possible predators is just to fart. A Sonoran coral snake will draw air into its cloaca, which is a single hole used for urination and feces, and then release it with a popping sound when it feels threatened. This “cloacal popping” is described by Rabiotti and Caruso as a “higher-pitched, shorter variant of a human fart.”
Only found in Mexico’s Cuatro Cienegas Reserve, the Bolson Pupfish holds the remarkable distinction of being an animal that needs to fart in order to survive. Gas is produced by the algae that the fish eat. The fish starts to float toward the surface, where hungry predators are waiting, as the gas builds up inside it. The fish can return to the sediment it often inhabits by farting.
American cockroaches are not only able to survive anywhere, but they can also fart.
Which animals can’t fart?
A few animals are incapable of farting, whereas others can but do not.
Despite their supposed ability, bats do not seem to fart. They may be able to avoid internal gas buildup because they digest their meal so rapidly. Theoretically, most creatures that digest their food are capable of farting; however, they may not do so so often or audibly.
The digestive systems of animals that are actually incapable of farting are unable to break down food in a way that produces gas inside a closed space, such as an intestine, and then expels it. For instance, a Portuguese man o’ war cannot fart. In its tentacles, the man o’ war liquefies its prey, which is technically a colony of specialized organisms.
According to Rabiotti and Caruso, birds generally do not fart because their gut microbes are different from those of mammals and their food goes through their digestive systems fast, leaving no opportunity for gas buildup. Whether amphibians toot is up for debate. Because frogs have weak sphincter muscles, it is unlikely that passing any gas would result in vibrations that are loud enough to be heard.
Sloths are an anomaly among animals in that they do not fart. Although their gut microbiota creates methane, which they ingest and exhale rather than release as farts, they digest their simple food very slowly.
