As the boy and girl in the book hang breathlessly over ledges and peek out from the tops of the trees, what do you think they're looking for exactly? A rare celebrity sighting? A to-be-unfolded prank on a classmate? Bigfoot?
Nope. They're watching for the creatures that go by, and go by they do—over and over again. They first appear running by (31-34) as the children watch in the "hot, hot sun." This is also the first time the refrain of the book, "What a lot of funny things go by" (37-38) appears.
Coincidence? We think not. Indeed, a lot of funny things do go by during the course of the book, starting on the next page when we see a whole parade of creatures in a long, winding line that stretches into the distance.
This happens all over again when the boy and girl watch a delighted line of sheep mince by in the moonlight:
By the light of the moon,
by the light of a star,
they walked all night
from near to far. (164-167)
So what do all of these traveling, traversing creatures do for the story? Well, they certainly add to the flow of quirky characters and illustrations that the reader sees. But they also represent all of the interesting different things that pop up every day in life, and how the boy and girl keep an eye out because they don't wanna miss a thing.