The theme of Joyful Noise is the life cycle of insects. Through verbal recreation of the sounds made by insects, the poems relate the birth of bounding grasshoppers and dreaming butterflies, the courtship of lovesick moths and contrary book lice, the death of frenzied mayflies and digger wasps.

In his Newbery acceptance speech, the author told how he selected the insects he would include, "Some were chosen purely for their musical possibilities, most struck me as metaphors for myself." Through their verbal duets, one comes to know the book's fourteen insect characters. The queen honeybee describes her "best" life of luxury, while the worker describes his "worst" life of toil. Water striders walk on water and water boatmen row, row, row. Each of the insect voices is charming and believable.