You can also view previously answered questions in the HSW Question Archive . Answer Fireflies or lightning bugs make light within their bodies. This process is called bioluminescence and is shared by many other organisms, mostly sea-living or marine organisms.
Fireflies light up to attract a mate.
To do this, the fireflies contain specialized cells in their abdomen that make light . The cells contain a chemical called luciferin and make an enzyme called luciferase . To make light, the luciferin combines with oxygen to form an inactive molecule called oxyluciferin . The cells that make the light also have uric acid crystals in them that help to reflect the light away from the abdomen. Finally, the oxygen is supplied to the cells through a tube in the abdomen called the abdominal trachea .