I absolutely love science, specifically marine biology, because of stuff like this. Those fish evolved to have what is known as a Lateral Line Organ (LLO) that senses changes in the water around them, which is what allows schools of fish to have such accurate synchronized movements, while also allowing them to evade and confuse the LLO and Electrosensory Systems (ESS) of predatory fish when together in a school.

Science is fucking awesome.