If you’ve spent any time outside on a summer evening, you’ve likely seen both lightning bugs flickering through the twilight and boxelder bugs sunning themselves on the side of a house. But despite both being common backyard insects, lightning bugs and boxelder bugs couldn’t be more different. Let’s break down what sets them apart!
What Are They?
Lightning Bugs (a.k.a. Fireflies)
Despite their name, lightning bugs aren’t actually flies. They’re beetles! These fascinating insects belong to the Lampyridae family and are best known for their bioluminescent glow, which they use to attract mates (and sometimes prey). Their magical lights are produced through a chemical reaction in their lower abdomen.
Boxelder Bugs
Boxelder bugs are true bugs in the Hemiptera order. They get their name because they’re most commonly found on or near boxelder trees, though they’ll also show up around other maples. While they don’t glow or fly gracefully like lightning bugs, they do show up in large numbers, especially in late summer and fall, seeking warmth and shelter.
What Do They Look Like?
Lightning Bugs
Boxelder Bugs
- Size: About ½ inch long
- Color: Usually dark brown or black with yellow or orange markings
- Special Feature: A glowing abdomen!
- Size: Slightly over ½ inch
- Color: Black with red or orange lines on their wings and thorax
- Special Feature: None bioluminescent—just striking markings
Where and When Do You See Them?
Lightning Bugs
Boxelder Bugs
Time: Dusk and night, typically in summer
Place: Open grassy areas, near water, meadows, and forest edges
Behavior: Flying low, flashing lights in a mating dance
Time: Daytime, especially sunny afternoons in late summer/fall
Place: On warm surfaces like house siding, rocks, or tree trunks
Behavior: Clustering in large groups, crawling more than flying
Are They Harmful?
Lightning Bugs
Boxelder Bugs
Not at all. They’re completely harmless to humans and pets. In fact, they’re beneficial for the environment and even considered indicators of healthy ecosystems.
Also harmless to humans—they don’t bite, sting, or transmit diseases. However, they can be a nuisance when they invade homes in the fall to seek shelter from the cold. They may also stain surfaces with their excrement.
Fun Fact Showdown
Lighting Bugs
Boxelder Bugs
Their light is the most efficient in the natural world—nearly 100% of the energy is converted to light with no heat!
They release a pungent odor when disturbed, which helps deter predators (and people!).