STEM fun for smart tots! Meet Mia, Ava, Oli, and Seb: they're the four engaging characters created by Harriet Blackford to introduce very young children to STEM concepts. This simple story, enhanced by Mike Henson's humorous illustrations and fun-to-do experiments, makes a fascinating subject come alive for preschoolers Everybody poos! But why? This fun book explores the process of digestion, what happens when we eat, and the waste that's left over.