Floating blinks of yellow, green, and orange light are typically sure signs of bioluminescent beetles, or as you likely know them, fireflies. Researchers recently nailed down the exact chemical reaction that gives fireflies their glow—information that had eluded them for decades. Sarah Sander, a postdoctoral associate who studies the evolution of light color in these often luminous insects, explains how this new finding affects her work. She also elaborates on why fireflies benefit from flashing in the first place, be it to attract mates or prey. Plus, learn to “talk” like a firefly using this nature guide.