Their teeth are brushed, their pajamas are on, and the moment their mama leaves the room all five monkeys start jumping on the bed. One falls off and bumps his head. Mama calls the doctor. The doctor says what the doctor always says. Then there are four, and the whole thing starts again.

Eileen Christelow turned a nursery rhyme into a book children can run themselves. They count down without being asked, they say the doctor's line before you get to it, and they watch for which monkey goes next. That is why it survives the fortieth reading when other picture books do not.

Her monkeys are drawn in colored pencil with real expressions on them, five distinct characters in five different pairs of pajamas rather than five copies of the same animal, so a child picks a favorite by the second page. The ending, which involves the parents, is the joke every adult reading it aloud waits for.

This is the Clarion paperback: 32 pages, light enough to go in a diaper bag and cheap enough that a chewed corner is not a disaster. Written and illustrated by Eileen Christelow. Clarion Books, an imprint of HarperCollins, first published 1989. ISBN-13 9780395557013.