Insects, for instance,

have no voice and no language, but they can
emit sound by internal air or wind, though not by the emission of
air or wind; for no insects are capable of respiration. But some of
them make a humming noise, like the bee and the other winged
insects; and others are said to sing, as the cicada. And all these
latter insects make their special noises by means of the membrane that
is underneath the 'hypozoma'-those insects, that is to say, whose body
is thus divided; as for instance, one species of cicada, which makes
the sound by means of the friction of the air. Flies and bees, and the
like, produce their special noise by opening and shutting their
wings in the act of flying; for the noise made is by the friction of
air between the wings when in motion. The noise made by grasshoppers
is produced by rubbing or reverberating with their long hind-legs.