Illuminating Findings

The flickering lights of fireflies have charmed children for centuries

The flickering lights of fireflies have charmed children for centuries. They have also puzzled researchers, who wondered how the creatures pulse their love lights so precisely. A group of Boston scientists recently solved this mystery. They found that fireflies produce nitric oxide, a gas also found in the human body. The gas turns off energy-producing structures in the creature's abdominal lantern cells, prompting a flash, then quickly dissipates. "Amazingly," says researcher Barry Trimmer, "it's a temporary cut in the power supply that probably triggers the firefly flash."