Researchers say that fruit flies may be attracted to and can taste carbon dioxide dissolved in water. Scientists at the University of California in Berkeley, in a study funded by the National Institute on Deafness and Other Communication Disorders, one of the National Institutes of Health, believe that this may help the diminutive insects to look for overripe or potentially toxic foods.

“Fruit flies contain similar versions of many human genes, which is why we study them for a variety of health issues, including taste,” says James F. Battey Jr., director of the NIDCD. “This research raises the question of whether people also may have the ability to taste carbon dioxide and perhaps other chemicals in food. If this were found to be true, our sense of taste could be even more complex than we realize.”
The study also found that it may be used as merely a flavor enhancer since it offers no nutritional value to the fly. After we saw this view of one laying an egg, we immediately rinsed out our half-empty Cokes, twice.