Fireflies (IMAGE) Trinity College Dublin Caption Fireflies light up the night sky. Although they exhibit random, individual behaviour (when they flash), groups of closely aligned flies will synchronise over time. Credit Rajesh Rajput Usage Restrictions No restrictions. License CC0 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.