You might not really be sure you saw what you think you saw when the first one shows up. But you stare in the direction of the flicker of light and there it is again—the first firefly of the evening. If you are in good firefly habitat, soon there are dozens, or even hundreds, of the insects flying about, flashing their mysterious signals.
Click here for original story, How fireflies glow and what signals they’re sending
Source: Phys.org