According to legend, there was a kind of bird called the "Yidai" (a type of swallow) on the East China Sea.
The Yidai birds were slow to react. They could not fly very high and appeared clumsy and incapable.
However, when they moved, they always stayed in groups, depending on one another for survival. They flew and landed together.
When advancing, none dared to rush ahead rashly. When retreating, none dared to fall behind at will. When feeding, none dared to scramble to be first. All their activities were orderly.
In action, the Yidai always moved uniformly without any disorder. They relied on collective effort to avoid harm from the outside world.