The scientific term for the process of "chirping" is called stirdulation. Crickets don't actually have voices, rather, the "chirping" sound you hear is the male cricket rubbing his wings together. Crickets "chirp" for three different reasons: 1.) To attract a female cricket 2.) To impress the female after he has already gotten her attention 3.) To communicate that other males should stay away. Listen to crickets chirping by clicking on the video below.