The weather is getting warmer, and flies are starting to appear. What happens when food is crawled over by flies? Ron Harrison, an entomologist at Orkin Pest Control, says that flies typically carry more than 200 harmful pathogens. Even if they only stay on food for one second, they can "transfer" bacteria onto it.
In addition, flies do not have chewing ability, so they will first spray their own digestive enzymes onto the food before eating it. Given that flies can spread diseases such as cholera, dysentery, and typhoid, it is best not to eat food that has been crawled over by flies. At the very least, the part that the fly has crawled on should be thrown away.