What causes the firefly to glow resulting in the light production seen in this picture?
Correct answer: A chemical reaction in light-emitting organs

Shamrock
Living in the Great Smoky Mountains National Park area, we have an annual tour to view the amazing synchronized firefly event. It’s a spectacular sight to see!

Player Elf Counsel
Player #3309479, There are glow worm caves in Tasmania. They are brilliant.

MoodyChef92025
Player #3309479, I have always wanted to see one of these little critters but we don't have them in California.

Rick-N-Bacher
they turn their flashlights on and off

KD
I wonder if those are the same compounds that are used to make glow sticks

Player #35721962
My first encounter with a firefly was in Corfu when l woke in the night to see a tiny light swirling above my bed. It frightened me as l didn’t know what it was. I soon found out. Fascinating!

Sport
grew up in Fontana CA and at times we'd see fireflies in the 60s and early 70s. in Arkansas I look forward to sunset to watch them.

Player #37355366
Only the males have the ability which is used to attract a mate

Tremain White
Perhaps that meant to read "...very sensitive to... light pollution..." as opposed to "population".

Player #2512936
Humans are destroying everything! Habitat loss; what a Shame!

Player #16702581
Player #3309479, synchronized?..like to music or do they all do the same dance moves?

FunTriv
Player #3309479, lucky you