To find out, scientists conducted experiments in a California lake, releasing flies and luring them into traps that contained fermented juice (and thus be able to determine the speed at which they fly). Additionally, the researchers installed a weather station to measure wind speed and direction at the release site throughout each experiment. The results of the research were published in the journal Proceedings of the National Academy of Sciences.
Thus, to carry out the research, the researchers posed the following question: Do flies behave differently when they are in the wild in search of food? In the 1970s and 1980s, a group of geneticists attempted to address this question by covering hundreds of thousands of flies with fluorescent dust and releasing them outdoors. To the surprise of the researchers, some flies appeared on rotten banana buckets at 15 miles away the next day.
However, according to Michael Dickinson, professor of Bioengineering and Aeronautics, no one had tried to repeat this experiment, so it was not known exactly how fast do flies fly and how many kilometers they can actually travel.