What would happen on a class trip if the worstbehaved boy in the class accidentally traded places with a chimp at the zoo? As the class continues on its field trip through town, the chimp's behavior as a "boy" becomes increasingly hilarious. The stern teacher doesn't realize the switch, but she gets fed up with the misbehavior and antics. Children will laugh aloud as the chimp wreaks havoc at the grocery store, library, and bank. Meanwhile, back at the zoo, the boy is having a very different day!