As viewers of the classic 1986 Jeff Goldblum film The Fly are well aware, the winged insect has some of the poorest table manners of any species on Earth. Lacking teeth to masticate solids, Musca domestica instead vomits out bile that can break down solids so they can be slurped back up.
The problem? Since common house flies are rarely invited to formal dinners, they pick up all kinds of pathogens and bacteria from all of the rotting garbage and feces they frequent.
Despite these habits, most people tend to swat away flies, thinking a brief landing on their cheeseburger is no big deal. But new research published in Scientific Reports and passed along by the Telegraph indicates that, impossible as it may sound, flies are even more disgusting than we knew.
An international team of researchers recently examined the various bacteria carried by the common house fly and the blowfly (Chrysomya megacephala)—which loves corpses—and discovered salmonella, E. coli, and H. pylori among hundreds of other types. Worse, these pathogens can collect on a fly's legs, meaning it wouldn't have to do a whole lot more than land on food to pollute it with bacteria that result in intestinal fireworks—and sometimes even serious conditions. (H. pylori, for example, can result in stomach ulcers.)
In short, flies spread disease wherever they roam, and even a passing stop on soup can leave behind bacteria that can ruin your meal, your day, or your digestive tract.
Editor's note: This post has been updated.