In this poem, Hughes uses the central metaphor of the titular thought fox to describe the writer's process of experiencing poetic inspiration to actually writing the poem down on the page. His imagination is represented by the midnight forest, a related metaphor that describes the fox's home. At first, the speaker jumps back and forth between his external reality—it is midnight, dark, starless, and lonely with only his clock and the blank page in front of him—and the world within his imagination, where the darkness is populated by trees and his sense that the fox is somewhere nearby. The fox moves "delicately," as a new idea just beginning to form within the speaker's mind might approach, gradually becoming more and more clear. Its nose is cold as it touches twigs and leaves, the fox's eyes flashing in the darkness, and it makes little foot prints in the snow, details slowly accumulating around and attaching to it, just as they might do with an idea that becomes more fully formed. At first, the speaker only sees the fox's shadow but can then see the fox's body, until, suddenly, he can smell the fox's "hot stink" when it is very near, an idea or text almost fully formed in the writer's head.
This metaphor seems to limit how much the writer can really do to affect his or her own inspiration and process. The writer can, as this writer does, prepare himself and go willingly into the midnight forest of his imagination. The writer can patiently await the fox, allowing the fox—like a new idea—to roam freely, to give it space so as not to disturb its wanderings and the details that accumulate around it. The writer can do all of this, but it is still possible that he might frighten the fox away, or even that the fox will not come at all. The writer, then, is rather at the mercy of the fox, a representation of his ideas and inspiration, instead of the other way around.