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. Why is it light during the day and dark at night? Kids can find out, and learn all about how our Earth revolves...