Since elementary school we have all understood that there is more than one type of fart. You’ve got the high-pitched Whistler, the stomach-churning Growler, the stealthy Crop Duster, and of course the Silent-But-Deadly. While thorough and expansive, these nicknames don’t really add much to the scientific discourse on flatulence, and no, your friend asks “What did you eat?” while frantically waving their hands in front of their faces does not count as scientific research.

However, there is hope for better understanding the hows and whys of farting. The Human Flatus Atlas has asked for volunteers to place wearable sensors in hopes of mapping the first atlas of intestinal gas. By placing a small smart device near their spiracles, participants can provide the organization with valuable data to aid in its mission to uncover the mystery of the human gastrointestinal system.

Farting, of course, has more to do with the body’s natural functions than simple comic relief. It is a natural byproduct of the digestive process. Your digestive tract creates gases such as hydrogen, carbon dioxide, and methane by breaking down undigested food in the large intestine or colon. Gas can also be caused by swallowing air, which can occur when you drink too quickly or, for example, chew gum.

As part of its research, HFA has broken things down into three essential categories of farts:

• There are “normal people,” which even the HFA admits they haven’t quite defined yet, saying on their official site: “You think you’re average. Maybe you are, maybe you’re not. Most people have no idea where they really fall. Put on the sensor, find out, and help us define what “normal” really means.”
• Then there are “hydrogen hyperproducers,” which they define as people who produce between 40 and 50 flatulences per day.”
• And finally, “Zen digesters,” who are people on a high-fiber diet who never seem to produce much gas.

Regardless, the frequency of farts is something to monitor, but as organizations like UnityPoint Health point out, you should also pay attention to the double sound and smell of farts.

For example, loud but not smelly farts can be caused by swallowing excess air (as mentioned above, eating too quickly, or drinking carbonated drinks). If it produces a rotten egg smell, it is likely the result of sulfur compounds in the intestine, often after eating high-protein meats, onions, garlic, or cruciferous vegetables such as broccoli and cabbage. If your farts smell sweet, this may indicate the presence of dimethyl sulfide or reflect a large amount of sugar, yeast, or specific foods such as asparagus and some cheeses. Those old “silent but deadly” farts can mean your body is breaking down specific proteins or suffers from an intolerance, such as lactose or gluten. Finally, burning farts can be caused by the passage of stomach acid or digestive enzymes, usually associated with diarrhea, spicy foods, or a sudden increase in fiber.

So what kind of fart are you? Next time you get carried away, pay attention… to the science.

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