Identify the narrator's variety of emotions surrounding the discovery of the snake at the well. Explain your reaction.

When the narrator first sees the snake in his water trough, he is mildly irritated. He reasons that, since the water trough belongs to him, he should not be made to feel like a "second comer." 
However, the narrator is also amused that the snake demonstrates little fear of him. The reptile alternately drinks and inspects him with the mild gaze of a curious bystander. The tone of the poem takes on a menacing quality, however, when the narrator decides that the snake must die. According to the narrator's voice of "education," golden Sicilian snakes must be killed because they are venomous. The narrator does not elaborate on the nature of this "voice of education," so we can only speculate on its origins. 
Perhaps, the voice of "education" refers to the narrator's gleaned knowledge about the snake, acquired through either formal or informal means. Another interpretation is that the narrator's "education" may have been acquired through painful experience. An additional interpretation rests on the biblical interpretation of the snake as a malevolent and dangerous symbol of temptation and evil.
The voice of the narrator's "education" is mingled with a condescending, contemptuous voice that goads him to execute the snake with a stick. This new voice suggests that the narrator's masculinity is in doubt. Interestingly, the narrator ignores both voices; he decides that he rather likes the fact that the snake has chosen to grace his water trough with its presence. His bravado is replaced with self-doubt, however:

Was it cowardice, that I dared not kill him? Was it perversity, that I longed to talk to him? Was it humility, to feel so honored?I felt so honored.

The narrator feels numerous emotions; however, he cannot quite decide whether he is a coward, a maverick, or merely a meek host. Once more, the contemptuous voice taunts him, suggesting that his cowardice is behind his decision to spare the snake's life. The narrator then admits that he is afraid of the snake. However, he is also strangely honored by the snake's presence. As he contemplates his conflicting emotions regarding the snake, the creature finishes drinking and begins to slither back into a hole in the garden wall.
Roused from his reverie, the narrator grabs a log and throws it in the snake's direction in the water trough. He immediately regrets his "paltry," "vulgar," and "mean" act. He confesses his disgust with the voices of his "accursed human education" and concludes that his "pettiness" needs to be "expiated." The narrator is clearly repulsed by his fear of the snake, and he characterizes this fear as an irrational one. 
As for your reaction to the snake, you will have to decide whether it is wise to kill a venomous snake or wiser still to leave a dangerous snake alone.