The
female glow worm is equipped with a marvelous lighting system. A wingless
beetle, she crawls about at night eating small
insects. On the lower side of her
abdomen she posesses a "lantern" which she uses to signal to her winged mate flying above. This "lantern" has a
transparent layer of skin. Behind this is an
oily layer of tissue which chemically produces the light, and a second layer which acts as a
reflector.
The glow worm is able to control this remarkably bright light, using it only at certain times to attract a mate. The male is equipped with particularly large eyes to enable him to see the signal. An abundant supply of oxygen and water is needed by the glow worn to maintain the chemical activity that produces the light. For a time, even the insect's eggs are
luminous.
Glow worms, which are about half an inch long, are
natives of
Europe.