Schools of fish are coordinated and social at the same time. They travel in schools of 50s and 60s and sometimes in the hundreds. It takes a school 4-6 fish to make it a comfortable school of fish. Fish swim in these schools for a few reasons. most of the time they are swimming in schools to protect themselves from prey and other creatures hunting them. Normally the bigger the school, the less likely they are to be eaten. When a school is larger, it creates a giant blob of shiny things much larger than the -prey and that scares them off.