What is the mongoose family's motto in "Rikki-Tikki-Tavi", and what does it imply about their characteristics?

Early in "Rikki-Tikki-Tavi," Kipling writes the following:

It is the hardest thing in the world to frighten a mongoose, because he is eaten up from nose to tail with curiosity. The motto of all the mongoose family is "Run and find out"; and Rikki-tikki was a true mongoose.

This passage joins together two key concepts, central to Rikki-tikki's characterization within this story. The first is curiosity. These animals, at least as far as Kipling presents them, are described as deeply curious creatures, always investigating the world around them. Thus, it should not be surprising if Rikki-tikki himself shows a great deal of curiosity as well.

However, Rikki's behavior (and the behavior implied within the motto "run and find out") conveys a quality of fearlessness, too. As you see throughout this story, Rikki-tikki is not a passive observer of the world around him, but rather a physically active and decisive participant within it. He shows little hesitation or second-guessing in his actions. This quality proves important because Kipling's mongoose is described as a martial animal. Thus, this same extraordinary courage will contribute greatly in battling the snakes.

How would you describe the mongoose in "Rikki-Tikki-Tavi"?

In Rudyard Kipling's "Rikki-Tikki-Tavi," he describes how a mongoose looks, sounds, and moves. Since this is a fantasy story, Kipling also gives the mongoose in this story, Rikki, a personality. A mongoose's fur and tail is similar to a cat's, but its head looks like a weasel's. When attacking or excited, it makes the chattering sound that gives Rikki his name: "Rikk-tikk-tikki-tikki-tchk!"

The way a mongoose moves is described in the story. First, Rikki almost always moves quickly. He is described as running, scuttling, and dancing along. He moves a lot. He is called a "restless companion" for Teddy because he gets up often during the night to check on things. A mongoose can jump faster than a snake can strike. Kipling points out no human eye "can follow the motion of a snake's head when it strikes," and people often mistakenly believe that a snake has bitten a mongoose, when in fact the mongoose has been able to jump clear of the snake. That's what Rikki does when Nagaina first goes after him from behind. When Rikki battles with Karait, the little snake, he performs a "peculiar rocking, swaying motion he had inherited from his family." Kipling says it looks funny, but it is very effective in fighting snakes. When he fights Nagaina, Rikki bounds all around and dances in a circle around her, avoiding her lightning-fast strikes. He then runs after her across the grass and catches her, latching onto her tail and going down the rat hole with her. His contented movement after his victory is to lick his whiskers and curl up in the grass to go to sleep. 

Rikki's personality in the story is what one might expect from a mongoose because of its behavior. Rikki is highly curious and needs to investigate everything. He is brave, as he is willing to face the huge cobra, Nag, even though he is still very young. He is clever, creating a plan to lure Nagaina away from her eggs so he can destroy them while they are easy to kill. He is persistent, not giving up until he has rid the garden of all the snakes.

After reading this story, readers have a good sense of a mongoose's looks, sounds, motions, and even potential (hypothetical) personality traits.