Fireflies:
SFX: (Bzz. Bzz. Nighttime ambience.)
     IS IT A MATING RITUAL? A WAY TO TRACK FOOD? SIMPLY A WAY TO PASS A
MIDSUMMER'S EVE?  SCIENTISTS AREN'T 100% SURE OF THE WHY BEHIND A FIREFLIES FIRE,
BUT THEY DO UNDERSTAND THE HOW.  ITS A PROCESS KNOWN AS CHEMILUNISCENCE AND
IT'S POSSIBLE BECAUSE THE FIREFLY PRODUCES TWO CHEMICALS CALLED LUCIFERINE AND
LUCIFERATE. 

     "At the appropriate timethe firefly mixes luciferine and luciferate together with
oxygen all at the right time in the right place in a specific place in its body."

     ITS A LOT LIKE THOSE GLOW IN THE DARK LIGHT STICKS THAT KIDS PLAY WITH OR
THAT CAMPERS USE.  THE LIGHT STICK HAS TWO SEPARATE COMPARTMENTS WITH TWO
CHEMICALS IN IT--YOU CRACK THE STICK, LETTING THE TWO CHEMICALS MIX AND VOILA--LIGHT.  WHETHER ITS A FIRE FLY OR A LIGHTSTICK, THE IMPORTANT STEP COMES WHEN THE
TWO CHEMICALS JOIN TOGETHER.    AS MOLECULES FROM THE DIFFERENT CHEMICALS 
BIND TO EACH OTHER THEY GIVE A KICK OF ENERGY TO SOME OF THE ELECTRONS.  BUT
ELECTRONS NEVER HOLD ON TO EXTRA ENERGY FOR LONG. 

     "That molecule then needs to get rid of its energy in some way.  It can sometimes
do it by colliding with other molecules and losing it through collisions,  but arrange the
system in a careful way, the excited product might have no other way to excite except
by physically releasing the energy as photons . . .  and the photon comes out as a form
of light and we see that as the burst given off by a firefly."

     LUCKILY FOR THE FIREFLIES, CHEMILUMINESCENCE GIVES OFF LIGHT BUT NEVER
HEAT --WHICH MEANS THAT ON A WARM SUMMER NIGHT FIREFLIES ARE VERY COOL
INDEED.