These Fireflies Flirt With Heart-Shaped Lanterns

Every species of flashing firefly uses a secret code to attract their mates—these ones do it with a light-up heart.

The heart-shaped light of a firefly in close-up

KQED Science

The insect world has all kinds of tricks up its sleeve. From astonishing feats of camouflage to 3D vision and other characteristics too numerous to list, insects may be tiny but they are marvels when it comes to their ingenious adaptations.

Take fireflies. Not only have they figured out the art of lighting up their bodies, but they do so by creating the most efficient light on Earth. They use that energy-efficient bioluminescence to attract mates, and some species even synchronize their flashes in a display we humans find rather dazzling.

Adding even more charm for firefly fans, female fireflies from the species, Photinus pyralis, make their bids for love (well, mating at least) with a heart-shaped light. Every firefly species has a special pattern to communicate with potential paramours. Like Mother Nature's own flashing emoji, when P. pyralis spies the special signal from a fellow-species fella, she twists her abdomen in his direction and reveals her secret heart.

KQED Science

The male of the species, known as the common eastern firefly or big dipper, is no slouch in the seduction department, either. He gets her attention by tracing out an acrobatic "J" in the sky, doing so in a big graceful dipping motion, hence the name.

KQED Science

And where does all this flirty flashing lead? When a love connection is made, as KQED Science explains in a video on the topic: "Our 'Big Dipper' comes bearing a 'nuptial gift,' a present of more than 200 assorted nutrients, kind of like a box of chocolates. Here’s the handoff. Some are lucibufagins—defensive chemicals fireflies secrete to ward off predators like spiders and birds. These defensive chemicals may help protect her."

And it also eventually leads to baby fireflies, complete with big dips and heart-shaped lanterns so that a new generation of fireflies can light up the nighttime sky with their special language of love.

Why This Matters to Treehugger

Wildlife is often the spark that nudges someone to want to take better care of the planet. At Treehugger, we believe that sharing the fascinating curiosities of animals, even seemingly inconsequential insects, can go a long way in inspiring people to want to live a more sustainable life.