Mystery of the Squirmy Wormy

Aviva miniaturizes Chris and Martin for a fascinating underground mission to meet earthworms and "dig up" the answer to the mystery of why worms come above ground when it rains. But they have to hurry, as they soon realize that life as a worm is full of dangers at every turn. Along the way they learn that wet objects can be changed by heating and cooling and that the worm's unique environment helps them stay moist.