The stanza form Burns uses for “To a Mouse” follows a strict AAABAB rhyme scheme. The A rhymes conclude the tetrameter lines, whereas the B rhymes conclude the dimeter lines. Although this stanza form contains fewer B rhymes than A rhymes, the B rhymes tend to have a more pronounced effect on the ear. This is partly because each stanza ends with a B rhyme, but also because the shorter lines that the B rhymes conclude are naturally punchier than the longer lines. The punchier nature of the B rhymes additionally stems from the way these rhymes provide a sense of closure that the A rhymes don’t. The three lines of iambic tetrameter that open each stanza set the ear up to expect a fourth line in the same meter. But instead of getting a fourth four-beat line, the poet inserts a two-beat line that ends with a different rhyme sound. When we eventually do get the fourth line of tetrameter we’d previously been expecting, we hear the A rhyme less distinctly than we would have had it come earlier. Thus, when another B rhyme repeats at the end, it emerges more distinctly than the A rhymes.

In addition to the more formal aspects of rhyme in the “Burns stanza,” it’s worth noting that Burns is unusual in the extent to which he makes use of feminine rhyme. Feminine rhyme refers to rhymes with multiple syllables, where only the first syllable is stressed. Feminine rhymes have a less forceful quality than so-called masculine rhymes, which fall on a single-stressed syllable at the end of a line. Although Burns does use masculine rhyme in the poem, most of the rhymes are feminine. Consider the opening stanza, which consists entirely of feminine rhymes (lines 1–6):

     Wee, sleeket, cowran, tim’rous beastie,
     O, what a panic’s in thy breastie!
     Thou need na start awa sae hasty,
               Wi’ bickerin
brattle!
     I wad be laith to rin an’ chase thee
             Wi’ murd’ring
pattle!

Both the A and B rhymes in this stanza feature two syllables, and in each case the stress falls on the first syllable. Note how these two-syllable rhymes sound less forceful than masculine rhymes like “fast” and “blast” (lines 26 and 27), or “dwell” and “cell” (lines 28 and 30). Note, too, that some of the rhymes in the above stanza don’t form perfect sonic matches. For instance, the words “beastie,” “breastie,” and “hasty” all have slightly different vowel sounds in the initial syllable, even though they all end with the same “-sty” sound. In addition to being feminine, these are also examples of slant rhyme.