Question

why do we live in flocks sticking close to each other

Answer 1

It is the law of nature. Any animal in the animal kingdom lives in a group. It is easier to survive in groups than alone. Evolution shows that species that stick together survive. It is just how we animals are programmed.  It is a natural instinct.

Answer 2

Penguins live in flocks sticking close to each other inorder to keep themself warm . Penguins are mammals which live in extremely cold places so, to keep their body warm and to safe themself from prey they stick to each other.