For a few reasons. The patterns of some fish when swimming in schools distracts or confuses a predator. In some cases they appear to be a single large creature rather than several small ones which can discourage most predators. Safety in numbers. If there are 300 people around you, the shark might get Bob instead of you.
A school
shawl of fish is spelt ....a shoal of fish which means a group of fish swimming together
A shoal - a large number fish swimming together
fish is a swimming animal and forest is a lot of trees that are close together.
a school of fish
a group of fish swimmimg together is called a school of fish
Shoal maybe
The general collective nouns for a group of fish are:a school of fisha shoal of fish
if it is not swimming it is dead!
Large groups of fish swimming together are better protected from predators than lone fish studyisland answr brok chick
The Scales.
by swimming fastly