High-speed video footage has revealed that movement aimed at the fly triggers an automatic escape reflex, causing it to jump forward and away from the threat.
To investigate the response of the common fruit fly, Gwyneth Card, from the California Institute of Technology in the United States, performed experiments in which black discs were dropped from different angles towards the flies. The findings were presented at the annual meeting of the Society for Experimental Biology in Barcelona.
Flies are capable of reacting to movement in one 50th of a second, and when fleeing predators - or a rolled-up newspaper - can make 90-degree turns in less than one-fiftythousandth of a second. So, swatting a fly is still as hard as ever.