The alluring firefly: nature's lightning bug may hold key to medical breakthroughs

The role of light in the mating rituals of adult fireflies was little understood until recently, but now scientists want to use bioluminescence for a host of potential medical procedures - including tagging tumors to monitor them

In a green clearing within the forest of Tlaxcala, Mexico, a campground waited for the sun to set.

Swarms of moms and dads stood next to abuelas nonchalantly chewing tamales from a nearby stand. Wriggling ninos flipped flashlights on and off, while overflowing trashcans marked meeting points.