What is the exposition of the story "Rikki-Tikki-Tavi?"

In terms of literature and standard plot charts, the exposition (or introduction) is a literary device that is used to introduce background information about events, settings, and characters to readers.
The exposition for "Rikki-Tikki-Tavi" is quick and straightforward. Readers are introduced to Rikki-Tikki as the main character that fought a war across many rooms of the big bungalow in Segowlee cantonment. We are also told that other animals in the area helped him out during the fighting. One of them is a tailorbird, and the other is a muskrat. It is an interesting exposition because it is a bit of a flashback. We are being told about things that Rikki-Tikki did before we are told about how Rikki-Tikki became involved with the house, its occupants, and other animals in the first place. 

This is the story of the great war that Rikki-tikki-tavi fought single-handed, through the bath-rooms of the big bungalow in Segowlee cantonment.

That information containing the details of the story does eventually get to readers, but it begins in the third paragraph.

One day, a high summer flood washed him out of the burrow where he lived with his father and mother, and carried him, kicking and clucking, down a roadside ditch.