Which detail from "Mowgli's Brothers" develops the theme that differences can make one an outsider?

The fact that Mowgli is a human develops the theme that differences can make one an outsider.

Explanation:

Mowgli Brothers is a short story which is written by Rudyard Kipling. The story is based on many themes of contrast between nature and nurture, and abandonment.

Mowgli is a boy who lives in jungle and adapt to the jungle way of living. But when he grows up as a human being, reality hits me and makes him aware that he can no longer be a part of jungle kingdom and he soon has to leave the place.

So in this story we get to known that Mowgli is an outsider and the fact that he's a human being is all that makes the difference.