Dante's poem begins as a household problem: something is scurrying inside the walls, and the speaker cannot find it. By the end the problem has moved indoors in a different sense. The rat is less a pest than a picture of something that has settled into the speaker's mind and will not leave. The poem never says so outright, which is part of its appeal. It lets the rat stay a rat while the details point to something more personal.
The turning point is a single line: the cheese and nuts "do not satisfy him as much as my thoughts." Up to then the speaker is a harassed homeowner trying the usual tricks. This line changes the stakes. Whatever is in the walls is feeding on the speaker's own inner life, and the headache ("your running is causing me a headache") starts to sound less like an inconvenience and more like a symptom. Even "I have suffered enough" suggests this has been going on longer than one night of scratching. Read this way, the poem is about anxiety or intrusive thoughts, though the text only suggests it. It never names the feeling, so the image has to do the work.
The sound of the rat is well chosen. His footsteps are "quick but heavy," a small contradiction that captures how a tiny worry can still feel enormous. He "gives away his spot" and bolts to "the next open space … before I find him." The thing you try to pin down always moves, which is how a nagging thought behaves when you turn to face it. The line about leaving "a trial of misfortune and commotion" reads as a slip for "trail." Whether or not it was meant, the word "trial" fits, because the speaker does feel put on trial in their own home.
The form matches the mood. There is no steady rhythm and almost no end rhyme. The early lines sprawl, with long breathless sentences that run on like the rat. Later lines tighten into short statements. The speaker talks the way a stressed person talks to themselves, in half-questions and corrections: "Who let him into my walls / Is there a hole I do not know about?" The unpunctuated first question and the question mark on the second give the passage an uneven, flustered sound. The poem also has a dry sense of humor. "Leave I tell him and he does not understand / Well of course he doesn't, he's a rat" is funny because the speaker catches their own foolishness mid-thought. Addressing him as "Mr. Rat" has the same effect: it is politeness and desperation at once. The humor keeps the poem from self-pity, and it makes the speaker easy to like.
The ending carries the most weight. Rhyme finally appears, quietly: "thin" and "in," then "lay" and "stayed." These echoes arrive just as the speaker stops asking who is to blame and starts examining themselves. "My walls are weak and thin / Maybe that's why you have ventured in." The title asks "How'd he get in," and the poem answers with an uncomfortable guess. The way in was the speaker's own lack of defenses. The possessive "my walls," repeated from the second line, now sounds like a description of the self: boundaries, protection, the things that are supposed to keep trouble out.
The final line, "It was an easy spot to lay and you stayed," is oddly gentle. There is no rage at the rat, and no triumphant removal either. The speaker understands why he came and why he remained, and that understanding is a kind of sympathy. The shift to the past tense ("stayed") also suggests the rat has been there for a while and may not be leaving.
The poem is significant for how much it gets from so little: one image, plain vocabulary, and an honest turn from blaming the intruder to questioning the house. It treats the experience of being troubled with humor, and it gives that experience a body and a sound. It also refuses a tidy resolution, which is more believable than a neat cure.