Fireflies are a fascinating sight at night. It’s no wonder they’re also known as lightning bugs. Neither flies nor bugs, fireflies are classified as beetles, living in meadows, forests, lawns and streams. Like all wildlife, fireflies are best left in their natural habitat, but if you manage to catch a few of these tiny flashing dancers, do everything you can to keep them alive.
TL;DR (Too Long; Didn't Read)
Keep fireflies in a jar with a small piece of apple and a clump of fresh grass, removing the lid and blowing across the top of the jar once a day. However, don't keep fireflies captive for more than a few days before releasing them back into the wild.
The safest way to catch fireflies is with a small net. As soon as they are caught, put them into a jar. Hold the jar upside down and position the net under it so the fireflies crawl up into the jar. Screw on the lid of the jar. Never punch holes in the lid because fireflies need damp air to survive, and air holes make the air inside the jar dry. The jar contains enough air to keep fireflies alive for at least one day.
Keeping Fireflies Alive
There's no need to feed adult fireflies because they did all their eating as larvae. Place a moistened piece of paper towel or a small piece of apple and a small amount of fresh grass into the jar with the fireflies. The paper towel maintains the moisture level in the jar and is something for the insects to attach to. They climb into the grass to hide.
Once a day, take the lid off the jar and gently blow across the top of the jar to freshen the air. Keep the jar in a place where it receives natural light but never place it in direct sunlight.
Letting Fireflies Go
While it's lovely to admire fireflies in a jar, you shouldn't keep them captive for more than two or three days. Fireflies have a short life span, so let them spend most of their days in the wild. Release your fireflies into a damp, vegetated area and pretend you're having your own firefly festival.
You can do a lot to protect fireflies. Give them lots of space to flash their lights and mate by turning outside lights off when they're not in use during the summer. Leave natural habitats alone. Don't take away rotting logs, which is a popular place for female fireflies to lay their eggs. Use only natural fertilizers in your garden and leave small areas of long grass on your lawn to give them places to mate.