The photo above showing lightning bugs accenting a darkened hollow was taken near Christiansburg, Virginia. In late spring and early summer lightning bugs, or fireflies as they’re sometimes called, are quite common in the eastern U.S. and in other parts of the world. Photographer: Ralph Clements

These bioluminescent insects (Lampyridae family) had just emerged after the passage of an evening thunderstorm — the scene is partially illuminated by a remnant lightning flash.

Lightning bugs rise up from the ground around dark (they stay hidden during the daylight hours) and start blinking their “mating lights.” As the night goes on, they rise a bit higher and each blink stays lit a tad longer. On occasion, thousands of these approximately one quarter inch (0.6 cm) long critters can be seen flashing on and off over fields, meadows and backyards. Some species even flash in synchrony. Lightning bugs are one of about three insects most people will tolerate.  Photo taken on May 26, 2011.