Question: why are farts so smelly?
Answer: All of these gases in the digestive system have to escape somehow, so they come out as farts! Gases are also what can make farts smell bad. Tiny amounts of hydrogen, carbon dioxide, and methane combine with hydrogen sulfide (say: SUHL-fyde) and ammonia (say: uh-MOW-nyuh) in the large intestine to give gas its smell.