Heart Flies Group (IMAGE) NASA/Johnson Space Center Caption Groups of fruit flies studied in the Heart Flies investigation were housed in tubes with ventilated caps and pre-loaded with fly food. Credit NASA / Dominic Hart Usage Restrictions None License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.