British scientists (who else) have discovered that fish can communicate in rather bizarre ways. For one, herrings:
use their farts to communicate. The tiny fish release a 22 khz sound, followed by a stream of air bubbles, from their anus. This sound and the ensuing signal are not released due to fear or diet, but they can be detected by other herring. They tend to fart in darkness when there are other herring nearby, reinforcing the idea that they're sending messages.I tend to fart in bed when my wife is present, reinforcing her idea that I am a pig.