archaea are actually the only known organisms capable of producing methane. the farts of lots of animals, including many (but surprisingly, not all) humans, contain methane because of symbiotic methanogenic archaea living in the gut.
so the next time you rip a real bodacious toot,
think of the strange and beautiful symbiotic conglomeration of organisms that is your body, and take a moment to thank archaea for their very special contribution.