They are bioluminescent insects, but we know them better as lightning bugs, or fireflies. They are one of the joys of childhood, when you chase them over a dewy lawn at night, and trap them in a jar, to light up your bedroom. But why don't we see them in the daytime?

To understand that, it helps to first understand how an insect can produce light. This photic quality is the result of a combination of chemicals produced by the insect: luciferin (substrate) plus luciferase (an enzyme) and adenosine triphosphate, results in light flashes when oxygen is added. But this chemical production does not take place in the daytime.

The firefly's flashing occurs in direct proportion to the amount of ambient light in the environment. They are seen more easily if outdoor lighting is turned off, and are less evident on nights when the moon is full, and the sky clear.

Their lifespan is a mere six days or so, during which, they spend most of the time seeking mates. Males, who have specific flash patterns, take flight at night and cruise in towards the ground where females are often waiting for romance to call. If they are attracted to the male's photic qualities, she will send back light signals of her own, and the male will reply, then land to check out his chances of getting lucky.