Crickets are insects in the order Orthoptera. They are relatives of grasshoppers, locusts, and katydids. Like these other insects, crickets have a pair of rear legs much longer and stronger than the others.
In some cricket species, such as the camel cricket, these powerful legs allow them to jump long distances. Other types of crickets can barely jump at all. However, even in this case, their legs still serve a purpose.
Male crickets create the distinctive cricket chirping that attracts female crickets to mate. Male crickets can chirp either by rubbing their legs along their wings' foretips or simply by rubbing their wings together. Creating these songs helps them attract mates.