Work it out
What did you see?
Fireflies are told apart by what their light does, not by how they look. Answer what you noticed — say "not sure" as often as you need — and we'll narrow it down.
Question 1 of 4
What did the light do?
The rhythm is the single most useful clue. Watch one insect for half a minute.
A field guide to living light
- Common eastern Photinus pyralis
A single warm-yellow flash in a rising J-shaped swoop, about once every 5–6 seconds
- Mangrove synchronous Pteroptyx spp.
Rapid, tightly synchronous flashing — whole trees pulse together, several flashes per second
- Asian firefly Luciola spp.
Quick, greenish flashes, often many at once, low over water and wet fields
- Common glow-worm Lampyris noctiluca
No flash — the flightless female emits a steady green glow to attract flying males
- Blue ghost Phausis reticulata
A steady blue-white glow held for up to a minute — not a blink — as the male drifts low