D major. Allegro. In ternary form: Introduction (mm. 1-2) – A (mm. 3-11) – B (mm. 12-19) – A' (mm. 20-25).

The opening two measures, with their appoggiaturas, staccato, and lowered third (F♮), evoke a lively and comical atmosphere. According to the composer, the quarter-note and eighth-note accompaniment figure in the left hand of section A depicts the movement of a caterpillar. Section B, with its continuous modulations to distant keys, can be said to represent a scene change, an “exploration.”