Crickets are insects related to bush crickets, and, more distantly, to grasshoppers. They have mainly cylindrical bodies, round heads, and long antennae. Behind the head is a smooth, robust pronotum. The abdomen ends in a pair of long spikes.The hind legs have enlarged femora (thighs), providing power for jumping. The front wings are adapted as tough, leathery wing covers, and some crickets chirp by rubbing parts of these together. The hind wings are membranous and folded when not in use for flight. many species, however, are flightless. The largest members of the family are the bull crickets which are up to 2 in long.
They are more than 900 species of crickets which are distributed all around the world except at latitudes 55° or higher, with the greatest diversity being in the tropics. They occur in varied habitats from grassland, bushes, and forests to marshes, beaches, and caves. Crickets are mainly nocturnal , and are best known for the loud, persistent, chirping song of males trying to attract females, although some species are mute. The singing species have good hearing, via the tympana (eardrums) on the tibiae of the front legs.