It started with a speck of light, followed by another and another, lighting up the patch of woods next to the cabin. At first we thought someone hung a disco ball, put a spot light on it and made it spin. We soon realized it was lightning bugs, whooping it up on a beautiful summer night during my family vacation in Grand Rapids, Minnesota.
The flash dance in the grass was created by fireflies, also known as lightning bugs. Their ability to set their little bodies aglow made them a favorite part of enjoying the wonders of nature after an active summer day on a Minnesota lake. I remember summer vacations at Grandma and Grandpa’s house where I caught fireflies in a jar and watched the small bugs crawl up the glass. Back then I was just as excited at being out after dark as capturing a bug in a jar. Now I’m excited to share that experience with my children and learn more about these creatures and their glow.
Let’s start with a basic fact: fireflies aren’t flies and lightning bugs aren’t true bugs. They are beetles in the Lampyridae family. There are many firefly species found throughout the world – over one hundred species occur in North America. In general, fireflies have soft, brown bodies and are half an inch to one inch long. Each species prefers a specific type of habitat, such as swamp, woodland, or suburban lawn.
Fireflies shine their light to attract a mate. Up in the air, the male lifts his wings and sends out a glowing signal. The female responds from the ground, and the two continue to signal one another until they meet.
How does a lightning bug create its summertime glow? The light is a chemical reaction that takes place in its abdomen. Inside special cells, a pigment called luciferin and an enzyme called luciferase combine with oxygen to produce light. The light bounces off reflector cells and then shines through the insect’s transparent skin, creating a flash for a potential mate and a nighttime show for human observers.
The “disco ball” display we saw at the cabin was one of many wonderful memories created during our family vacation, an event we hope to continue as often as we can.