“The Armadillo” has 40 lines arranged in 10 stanzas. Each stanza contains four lines. The syllable count in these four lines ranges widely, from five syllables to 11 syllables. In other words, the lines do not follow a strict metrical pattern. This lack of consistent meter points toward the poem being free verse. However, unlike some free verse poems, “The Armadillo” has a consistent rhyme scheme. The second and fourth lines of every stanza rhyme (ABCB). In the first stanza, the first and third lines also rhyme. In the second stanza, a rhyme from the first stanza is repeated. The rhyme scheme of the first two stanzas is ABAB CDBD. The repeated rhyme in these two stanzas (the -ight sound in “night,” “height,” and “light” [Lines 2, 4, 7]) returns in the seventh stanza with “white” and “sight” (Lines 26, 28).

Bishop uses some slant rhymes and visual rhymes. An example of a slant rhyme is in the sixth stanza, where the second and fourth lines end with “fire” and “pair” (Lines 22, 24). These words almost sound the same, but not quite, making the rhyme slant.