Tiny Creatures: The World of Microbes
by Nicola Davies
illustrated by Emily Sutton
Simple straight-forward prose and colourful illustrations form a good introduction to the minuscule world of microbes. Davies uses easy-to-follow analogies so kids can grasp just how tiny and numerous microbes are, while Sutton's double-page spreads show how quickly microbes multiply, and even how pretty some of them look.
An excellent book for three to five-year-olds.