Glow worm facts

   The glowworm or glow worm is a beetle famous for emitting light. The common glowworm of English literature (Lampyris noctiluca) is the wingless and, therefore, wormlike female of a beetle closely related to our firefly. This insect is about half an inch long, black, with dusky reddish legs and a marginal line of the same color. Like our firefly, the glowworm is nocturnal. The last segments of its body emit a steady, strong, soft, bluish gleam. As the light-giving female has no wings, it is easily caught. A couplet from Hamlet gives a glimpse of the hours Shakespeare kept and of his keen observation:
    The glowworm shows the matin to be near, 
    And 'gins to palé his uneffectual fire.
  Evidently the poet did not know that it is the female that glows. "The glow­worm," said Mr. Edison, "can do something we have not learned to do. It can give light without heat."

Some glow worm facts

• Glow worms are actually glowing insect larvae.
• The chemical reaction in the glow worm is very efficient; nearly 100% of the energy input is turned into light (compared to the best light-emitting diodes at just 22%).
• Glow worms can be found living in woodlands and caves throughout the world, except for the New World.
• These little insects can even survive above the Arctic circle.
• Adult females that glow do so to attract a male for mating.
• The glowworm is usually about 1 to 2 inches (2.5 to 5 cm) in length and will survive for about five months.