The luminescence is generated by the combination of a blood enzyme (luciferase), a protein (luciferin), oxygen and a natural acid, adenosine triphosphate, which in living organisms has the ability to convert sugars and fats into energy . This, in the presence of luciferase, luciferin and oxygen turns into light. These substances are found in a part of the abdomen, crossed by tiny air channels, between two walls: the front one is made of chitin, a transparent substance, the back one has a parabolic shape and, thanks to the presence of microcrystals, has a reflecting function. Just like in a lighthouse. The flashing has the function of sexual recall that the male addresses to the female.