There are three biological meanings of fish schools: one is spawning, foraging and migration. The second is the defensive role. Clustering makes it impossible for the enemy to do harm, and it is the illusion of a huge individual to make fierce fish produce shoals, so they dare not attack. Sometimes the fish will disperse quickly when attacked, which will make the fierce fish at a loss. Clustering also helps fish escape from moving nets. When only some fish are surrounded by nets, they can usually escape. Thirdly, when a fish swims, it can also form hydrodynamic conditions conducive to swimming, which reduces the resistance compared with a single action and has the highest swimming effect.

But there are also shortcomings: first, it is too concentrated and has a big goal, which is easy to attract the attention of fierce fish and cause a lot of danger of being caught.

Second, the supply of food organisms is sometimes limited, and tourists are easily eaten up by larger fish schools, so they often grow slowly because of insufficient nutrition.