At the beach, some tiny brown minnows swim near your legs. They come closer and closer and then they turn, all at once. If just one fish senses danger, it darts away. Then the fish next to it turns in a flash. The fish copy each other so quickly that they seem to be moving at the same time.
Some kinds of fish swim in groups called schools or shoals. There might be thousands of fish in the school, but they act as one. They all swim the same way, at the same speed. Fish swim in schools to stay safe. One fish swimming alone is an easy meal for a bigger creature or an easy target for somebody’s fishing net. But a large group can confuse an enemy.
It is also easier for fish in schools to find food, because thousands of pairs of eyes are on the lookout. If one fish spots food and turns towards it, the whole school follows.
Not all fish live in schools. Fish that hunt prey, such as sharks, usually live by themselves. Other fish form schools only when they eat, rest, or lay eggs, or when they are young.
Picture Credit : Google