Schooling Fish

One of the most enjoyable scenes in an aquarium is a group of fish swimming in unison, changing directions in an instant, yet never colliding with each other.

How are they able to swim in unison? Why do some fish swim alone while others spend their whole lives in schools? What is the purpose for swimming in a school? The answers to these questions are not completely known, but we do know some interesting things about schooling behavior in fish.