Animals That Fart
Flatulence is not a uniquely human experience — it is a fundamental feature of the vertebrate digestive system. From tiny herring to massive elephants, the animal kingdom farts with impressive diversity, frequency, and in some cases, strategic purpose.
Why Animals Fart
Any animal with a gut microbiome that performs fermentation will produce intestinal gas. This includes all mammals, most birds, reptiles, and even some fish and invertebrates. The gas is a byproduct of bacterial decomposition of undigested food material — the same process that occurs in humans. Herbivores tend to be the most prolific gas producers because plant matter (particularly cellulose and complex fibers) requires extensive microbial fermentation to break down. Carnivores, with shorter digestive tracts and more easily digested protein-based diets, generally produce less gas.
Cows: The Climate Concern
Cattle are the most discussed farters in the context of environmental science. A single cow produces between 250 and 500 liters of methane per day — primarily through a process called enteric fermentation in the rumen, a specialized stomach compartment. Crucially, most of this methane exits via belching rather than flatulence, but the distinction is academic for climate purposes. The world's 1.5 billion cattle collectively contribute approximately 14.5% of global greenhouse gas emissions, according to the FAO. This has made bovine digestion one of the most politically consequential digestive processes on Earth.
Herring: The Strategic Farters
In one of the more remarkable discoveries in marine biology, Atlantic and Pacific herring were found to communicate via flatulence. The fish release bursts of gas from their swim bladders through the anal duct — producing a high-frequency sound dubbed Fast Repetitive Tick (FRT) by researchers. Crucially, herring produce these sounds primarily at night and in groups, suggesting the behavior serves as a contact call to maintain school cohesion in darkness. The discovery earned the researchers an Ig Nobel Prize in Biology in 2004 — awarded for research that 'first makes you laugh, then makes you think.'
Animals That Cannot Fart
Not all animals can fart. Birds lack the gut bacteria required for fermentation-based gas production, meaning bird flatulence is essentially nonexistent — a fact that surprises most people given the voluminous diet many birds consume. Sloths are anatomically and metabolically unusual: their extremely slow digestion and low body temperature suppresses fermentation to near-zero. Octopuses and most other cephalopods have short digestive tracts with minimal microbial fermentation. Interestingly, while marine mammals like dolphins and whales do fart, their flatulence has only rarely been documented — though whale farts have reportedly been described as 'the worst smell imaginable' by unfortunate researchers.
Animal Fart Facts
- A single cow produces 250–500 liters of methane per day, mostly via belching.
- Herring use flatulence as a form of communication — producing an anal sound called FRT.
- Termites collectively produce more methane than all the world's cattle combined.
- Dogs and cats fart, but their short digestive tracts mean less fermentation than humans.
Fun Fact
The manatee — a large, gentle aquatic mammal — stores intestinal gas in its hindgut to control buoyancy. When a manatee needs to dive, it releases intestinal gas. When it needs to surface, it retains it. A manatee's ability to swim is literally powered by holding in its farts.
Sources
- Wilson, B. et al. (2004). Pacific and Atlantic herring produce burst pulse sounds. Proceedings of the Royal Society B.
- FAO (2013). Tackling Climate Change Through Livestock. Food and Agriculture Organization of the United Nations.