Part II of Nancy Kelly Allen's article, The Funny Business of Writing Humor for Kids.

As children develop language skills, the humor of rhymes and nonsense words make them laugh. Preschool aged kids are attuned to the sound of words. They enjoy the playful sound of repeated variations of a word—catty, batty, fatty, watty. Calling a familiar word by the wrong name, such as referring to the nose as an ear, is just downright funny to them. They also find misplacement of a body parts comical—a dog with two legs up and two legs down or a donkey’s head on a turtle’s body. Exaggeration is laughable to this group—a car that is too long or too tall, oversized eyes, or a basketball for a head. They also find impossible behavior funny—a cow jumping over the moon, a talking dog, or a snake that wears underwear. Rhymes, alliteration, and rhythmic text please them.

When kids enter school, they still love wordplay, exaggeration, and physical or slapstick humor. They also enjoy simple riddles and jokes, especially potty humor, and rhyming and nonsense words. Dr. Seuss books are a hit.

Older kids, seven and up, have a better grasp of the language. They love jokes, riddles and other brainteasers, puns, and potty humor. This is the age when chapter books and middle-grade novels are devoured on various subjects. By age eleven, children gain a better understanding of complex literary devices and appreciate humor in irony and sarcasm.