What Really Happens When A Fly Lands In Your Food

If you're wondering what that fly is doing in your soup — chances are it's doing more than just the backstroke.

While that's an adapted punchline of a well-worn joke, a fly actually landing in your soup — or on any other food you're about to eat for that matter — is no joke.

According to Insider, when a fly lands in your food, chances are it will be regurgitating its saliva directly onto your next bite. Flies have no teeth, so the only way they are able to eat is by liquifying the food they land on, and then sucking in the fluid through their trunk-like nose.

Gross enough for you? It gets worse. 

Flies do not discriminate when it comes to their diet, meaning they are happy to dine on all kinds of disgusting stuff, including rotten meat and feces. So, when a fly lands in your soup, it then regurgitates all of that bacterial goodness right into your goulash.

Mmm. Delicious, huh? Bet you wouldn't have guessed that typhoid fever, cholera, and tuberculosis were possible ingredients in your meal.

Is it safe to eat food that a fly lands on?

At some point or another, you've likely eaten food after a fly has briefly landed on it. And while experts say there is some risk in doing this — chances are you have not been risking your life.

Thomas J. Daniels, Ph.D., associate research scientist and director of Fordham University's Vector Ecology Lab at its Louis Calder Center, says that house flies can carry over 100 different pathogens, such as E. coli, salmonella, and hepatitis A. He explains, "We're potentially at risk even from a fly landing on food, though the amount of pathogen transmitted is likely to be small," Daniels says (via The Healthy).

But if you were, say, at an outdoor barbecue and returned to your food 30 minutes later for a second helping of that delicious potato salad after a number of flies have been hanging out around your plate, you could be at a much greater risk for bacterial infection, according to William Kern, an entomologist at the University of Florida. However, he explains that the discomfort that might ensue from an infection would likely not last more than a few days and it would not pose a threat for a healthy person (via Vice).

The next time a fly lands in your soup, just be sure to shoo it away quickly before it has a chance to start feasting, and you won't need to worry about it further pestering you.