In many places the insects called fireflies are a familiar sight on summer nights. They are noticeable because they can produce flashes of light. Fireflies belong to the beetle family. They are also called lightning bugs.
There are about 1,900 species, or types, of firefly. They live in tropical and mild parts of the world. They generally like warm, humid areas, but some live in dry places.
Adult fireflies range in size from 0.2 to 1 inch (5 to 25 millimeters) long. They have a soft, flattened body that is dark brown or black, sometimes with orange or yellow marks. Males have wings and are good fliers. Females either have short wings or no wings. The females without wings are often called glowworms. Young fireflies, which also have no wings, are also called glowworms.
Fireflies produce light with special organs, or body parts, on the underside of the body. These organs make light by mixing chemicals with oxygen from the air. Fireflies make a certain series of flashes to attract a mate. When a possible mate sees the flashes, it returns the signal.