The bright flashes of lightning bugs are a sure sign that spring and summer are here. But have you ever wondered why these little insects glow so beautifully at night? They blink for a couple of important reasons. First, they signal mates (other members of their species) to find each other. But they also illuminate to tell predators that they don’t taste good.
The glow of a lightning bug is caused by chemical reactions in its body. That includes the presence of calcium, adenosine triphosphate and something called luciferin. This mixture of chemicals creates a light that the insect can use to communicate at night and attract a mate.
During the day, you may see them resting on the ground in tall grass or other vegetation. They like these spots because they provide cover and a good vantage point for broadcasting their nocturnal signals.
Males and females each have a distinct pattern they use to send out their signals. After a male sees the right signal from a female of his species, he will fly down to her and they will mate. Females then lay their eggs in damp soil. The eggs hatch into larvae that spend a year or more feeding on soft-bodied invertebrates, such as worms, snails and slugs.
Once the larvae mature into pupae, they change their diet to include plant pollen and nectar. Lightning bugs, which are also known as fireflies or glow worms, spend the majority of their lives in the larva and pupal stages. As adults, they only live a few weeks or less.