“To a Mouse” is structured as a direct address to a mouse that the speaker has disturbed from its underground nest while plowing his field. The speaker’s address to the mouse is organized into several parts, which could be schematized as follows:

   Stanzas 1–2: initial address and apology to the mouse
   Stanzas: 3–6: expression of remorse and projected understanding of the mouse’s situation
   Stanza 7: assertion of the sense of uncertainty he shares with the mouse
   Stanza 8: hypothesis that the speaker has it worse than the mouse

The fact that the speaker ends the poem by focusing on his own fate demonstrates the poem’s structural similarity to a verse genre known as dramatic monologue. This genre is typically characterized by a first-person speaker who inadvertently reveals aspects of themself in the course of their speech. In a dramatic monologue, the speaker is typically alone and not addressing anyone. Although the speaker of Burns’s poem is addressing a mouse, the fact that the mouse can’t understand him means that he’s effectively speaking to himself. Indeed, during his address he ultimately focuses on his own uncertain future, ending with the assertion that the mouse is blessed compared to him (line 43).

It’s worth noting what’s perhaps the most immediately noticeable structural element of the poem: the unique stanza form. Burns makes use of a stanza form called the “Habbie,” which is named after a sixteenth-century Scottish piper named Habbie Simpson. The poet Robert Sempill wrote a well-known elegy for Simpson in 1600 that featured this stanza form. Though not invented by Burns, he used the form in many of his poems, and for this reason the Habbie is also known as the “Burns stanza.” Regardless of the name, this stanza has a six-line form that features lines of iambic tetrameter as well as iambic dimeter. Lines 1, 2, 3, and 5 are written in tetrameter, and lines 4 and 6 feature half-lines of dimeter. What results from this metrical mixture is a structure that makes use of the songlike quality of iambic tetrameter, yet also dampens that quality with more abbreviated lines. The use of iambic dimeter brings greater rhythmic texture to the language, and it makes the speaker’s address to the mouse sound more conversational than would have been possible with lines of continuous tetrameter.