out to kill Rikki's adopted human family, but the little mongoose is even more determined to protect Teddy and his parents, and he does.

Little Rikki kills Nag first after foiling the cobra's plot to attack the humans in the bathroom. Then he kills Nagaina after bravely following her all the way down into her hole. He wisely destroys the cobras' eggs as well.

There are many themes in "Rikki-Tikki-Tavi," but the primary one, the one that seems to include all the others, is balance. Throughout the story, Rikki balances curiosity with caution, courage with practicality, and pride with humility.

As a mongoose, Rikki is a curious creature. This is how he meets his human family in the first place and how he discovers, as he explores the house and garden, the cobras' plot to kill his people. But Rikki, as curious as he is, is not careless. He approaches the snakes cautiously, for he is still young and not completely trained. He recognizes his limits and plans accordingly. He balances curiosity with caution.

Nonetheless, Rikki is a courageous mongoose. He bravely takes responsibility for protecting his family from evil in the form of snakes, and three times he saves their lives, willing to give up his own life if necessary to protect the people he has grown to love. The little mongoose is so brave that he even grabs onto Nagaina's tail and follows her down into her hole, knowing that he might never see daylight again. Yet Rikki balances his courage with practicality. He plans his moves carefully, trying to take the whole situation into consideration, including his risks and his limits. He knows when to push forward and when to back down.

Finally, Rikki balances pride with humility. By the end of the story, Rikki has every right to be proud of his accomplishments, and he is. He has defeated the evil cobras and protected his family. But Rikki is humble, too, and realizes that he has not destroyed all the evil in the world. He will be ready "with tooth and jump and spring and bite" to save the day again whenever he needs to and to continue to balance curiosity with caution, courage with practicality, and pride with humility.

The conflict in "Rikki-Tikki-Tavi" takes place between a mongoose determined to protect a family of humans and two cobras. The theme is protecting those you love at all cost, even if it means putting your own life at risk.

The story begins with the arrival in a garden of Rikki-tikki-tavi, who was washed up by a flood. Teddy, the young boy who lives in the bungalow, together with his parents, revive the tired mongoose and give him shelter. Rikki-tikki-tavi therefore feels immediate loyalty towards them.

Conflict soon arises between Rikki-tikki-tavi and a cobra couple named Nag and Nagaina, who do not want him there because of the threat that mongooses pose to snakes. The snakes attempt to kill him quickly, and it is thanks to Darzee's timeous warning that he escapes their first encounter unharmed.

Soon after this, the main theme comes to light when Rikki-tikki-tavi kills Karait, a snake who was lying in wait for Teddy. Later, the conflict between Rikki-tikki-tavi and Nag heats up as Rikki gets wind of a plot to kill the humans in order to get Rikki-tikki-tavi to leave. As Nag lies in wait to attack the family, he himself is attacked and killed by Rikki-tikki-tavi.

Knowing that the next stage in the conflict will involve taking on Nagaina, he resolves to destroy the cobra eggs that he has learned about. As Nagaina is about to attack the human family, which leads to the two descending into the cobra's lair. Rikki-tikki-tavi emerges victorious from the battle that follows, thereby ending the conflict and, in line with the theme, protecting the human family from future harm.

The conflict in Rikki-Tikki-Tavi is between Rikki, the protagonist, and the snakes, the antagonists. As stated in the first paragraph of the story, the conflict is a "great war." It is, in fact, a life-or-death struggle between Rikki and each snake he meets. 

There are several themes that come through in the story. First, Rikki's courage despite his youth and size emphasize the theme that even the young can stand up for what's right and fight against evil. Rikki's courage comes from his natural ability, but also from his firm conviction that snakes cause harm and devastation. Rikki confronts Nag when he first meets him, saying, "Do you think it is right for you to eat fledglings out of a nest?" The snakes represent a threat not just to animal life in the garden, but also to human life in the bungalow. Rikki overhears the sinister plans of Nag and Nagaina as they plot to kill the child, Teddy, and his parents. The cobras' motivations are nefarious; they want power and control, and they will kill to get it. Thus Rikki's battle against the snakes can inspire readers to stand and fight against evil, even if they are young or small.

Another theme that comes through in the story is that one should be humble when taking satisfaction from a job well done. Rikki spurns Darzee's foolish song of praise, preferring to focus on completing his work rather than listening to accolades. But when Rikki has disposed of Nag, the eggs, and Nagaina, he flops down in the grass for a well-deserved nap. He is satisfied with his accomplishment, but as the final paragraph states, "he did not grow too proud." Thus the story communicates that a job well done is worth savoring, but not worth boasting about. 

Rudyard Kipling wrote an entertaining story with a life-or-death struggle between good and evil that spurs readers to have the courage to stand and fight for what's right and to take satisfaction in their work without undue pride.

The main conflict of Kipling's enduring short story is Rikki's inevitable battles with the cobras, Nag and Nagaina. Rikki is aware of the cobras' deadly abilities, but his natural instinct takes over on two fronts: A mongoose's mortal enemy is the cobra, and his own fears become secondary when one is near; and, his other duty was to protect the human family which had befriended him. His own safety was less important than these two instinctual urges.

The story contains several different themes. Courage vs. fear is one. Man vs. nature is another. Kipling's military background focuses on the importance of loyalty and duty, and the Darwinian theories of the survival of the fittest is yet another example.

The might of the British Empire vs. the simple ideals of Indian culture is another theme.  It expounds Kipling's belief of the superiority of the white man (represented by the British family as well as Rikki) over the Hindu people (symbolically epitomized by the evil Nag and Nagaina and the cowardly Chuchundra).

Or you may want to refer to the enotes theme link below.

http://www.enotes.com/rikki-tikki/themes

The central conflict is between Rikki and the snakes and takes place in and around the yard.

A conflict is a struggle between opposing forces.  This story is actually deceptively complex.  While on the one hand it is a story of a mongoose protecting people from snakes, it is also an allegory of British imperialism in India.  Yes, the conflict is between Rikki and the snakes.  Yet there is a larger conflict going on here.  The snakes’ territory has been encroached on by the people, just as the Indians have been colonized by the British.

There are many types of conflicts in literature.  The most common are character vs. character (Rikki vs. snakes), character vs. self (Rikki’s fear, and the snakes’ fear of that they will not be up to the task of confronting Rikki, and character vs. nature (Rikki being washed away into the garden).  There is also character vs. society.  That one is the one that caused this whole thing in the first place—it is the colonialism that causes the people to be in the garden, and gives Rikki justification to protect them.

Rikki is an ordinary mongoose who is washed into the garden one day.  Like any other mongoose, he wants to be a “house mongoose” one day.  That means he wants to live with a family.  All mongooses have one thing in common—they kill snakes.  The conflict between Rikki and the snakes was thus inevitable.

[Though] Rikki-tikki had never met a live cobra before, his mother had fed him on dead ones, and he knew that all a grown mongoose's business in life was to fight and eat snakes. Nag knew that too, and at the bottom of his cold heart he was afraid.

Nag asks Rikki an interesting question. It is only meant to be a diversion so that his mate Nagaina can distract Rikki, but it is worth considering.

``Let us talk,'' he said. ``You eat eggs. Why should not I eat birds?''

There are two issues going on here.  First of all, we are predisposed as humans to root for the fluffy, cuddly mongoose as opposed to the creepy snakes, even though the mongoose is the aggressor here.  Second, the snake and the mongoose both are just doing what their instincts tell them to do.  There is no right and wrong here.  There is just nature vs. nature.  In fact, Rikki will later kill all of Nagaina's eggs, both to prevent the cobras from growing up, and to distract her.  Where is the morality in that?  Do we pity her, or the baby cobras?

The character vs. society conflict comes from the fact that this situation only arises from the colonial backdrop.  These people are in this garden, trying to cohabitate with snakes, and in this country, because for some reason they feel that they belong there.  They feel that they can take what they want.  That is the nature of colonialism.  It is what humans do to animals, and it is what the British are doing to the Indians.  The garden is described as “only half cultivated” because the people cannot quite control their domain.  They are strangers there.

On its surface, this is a children’s story of a snake versus a mongoose, the good and brave versus the evil.  But there is no good and evil here.  There is only nature.  Rikki was not acting out of some kind of good will toward the people.  He was acting on instinct.  He was doing what he was born to do.  So were the snakes.  We as people only identify with one of those.

The theme of "Rikki-Tikki-Tavi" is heroism—more specifically, the growth and development of a hero facing his first challenges, and the nature of his heroic qualities. In this, a children's story about an anthropomorphized mongoose is very similar to some of the greatest epics in literature, particularly Beowulf, the first part of which it resembles in structure. This is clearly Kipling's intention, since he begins the story by telling the reader,

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. Darzee, the tailor-bird, helped him, and Chuchundra, the musk-rat, who never comes out into the middle of the floor, but always creeps round by the wall, gave him advice; but Rikki-tikki did the real fighting.

Rikki, like all the great heroes, is a solitary figure, alone because he is without peer. The story begins with him a state of complete helplessness, apparently dead, and in truth very nearly so. Although the family rescues him and the other animals are on his side, he has to work out how to fight snakes for himself and rely on his own innate qualities in his journey to true heroism. These qualities include endless curiosity, alertness, and most of all, courage.

Rikki is also motivated by a strong sense of responsibility. He quickly adopts the human family, and makes it his mission to protect them, along with the animals in the garden. Like any hero, he soon discovers that he is exceptional and concludes that it is his duty to protect those who are not as strong and brave as he is.

The overarching theme in Rudyard Kipling's story “Rikki-Tikki-Tavi” is balance. The young mongoose Rikki-tikki-tavi strikes a balance between curiosity and caution, courage and practicality, and pride and humility. Let's see how he does it.

Rikki-tikki-tavi is, like all members of his mongoose family, a curious creature who seldom gets truly frightened by anything. His curiosity is what brings him into the house of Teddy and his family after they rescue him. Curiosity is what makes him explore the house and garden thoroughly and discover Nag and Nagaina, the cobras. Curiosity is what brings him to talk to the musk-rat Chuchundra and discover the cobras' plan to invade the house. Yet, for all his curiosity, Rikki-tikki-tavi is not a careless creature. He is cautious about how he approaches the snakes, knowing that he is still a young mongoose and not completely trained. He knows better than to go down their hole and take the offensive, for instance, and also than to attack Nag outright in the bathroom. Rikki-tikki-tavi balances curiosity with caution.

Even so, Rikki-tikki-tavi is a highly courageous creature. He recognizes evil when he sees it, and he takes responsibility for protecting his family. In fact, this young mongoose saves Teddy and his parents three times by bravely attacking, fighting, and killing the snakes, first Karait, then Nag, and finally Nagaina. Each time he is successful because he is willing to give his own life to protect others. He even holds onto Nagaina's tail and goes behind her down into her hole even though he knows he might never come back. Yet, for all his courage, Rikki-tikki-tavi is also practical. He strategizes and plans. He guides the bird Darzee's wife in creating a distraction so he can destroy the cobra eggs. He practically realizes what he can and cannot do and understands when to take a risk and when to back away. Rikki-tikki-tavi balances courage with practicality.

By the end of the story,, Rikki-tikki-tavi is rather proud of himself for his accomplishments, and he ought to be. He has saved many lives and gotten rid of a great evil. Yet Rikki-tikki-tavi is humble enough to refuse to grow too proud because he realizes that he cannot relax his guard or rest on his laurels. He needs to be ready “with tooth and jump and spring and bite” to meet any new cobra that dares to show up in his family's garden.

The most important theme of the story is undoubtedly courage. Rikki has to show remarkable bravery in defending Teddy and his parents from the deadly cobras Nag and Nagaina. Taking on these two enormous snakes doesn't come easily to Rikki; he's genuinely scared of them. Yet he knows that he must overcome his debilitating fears if he's to protect the human family to which he's become so attached.

Although Nag and Nagaina are so much bigger and stronger than Rikki, he doesn't think twice about backing down. He could be forgiven for running away from them in terror, as so many animals have done in the past. But he doesn't. He stands tall in the face of danger and attacks the cobras head on. Rikki is victorious, as the snakes and their eggs lie dead, and Teddy and his family are safe. This is all down to the little mongoose's remarkable courage.