The title says it all: Just the Right Size: Why Big Animals are Big and Little Animals are Little.

Just the Right Size by Nicola Davies

This great science picture book explores the size of living things from microbes to whales and the factors that influence their size. There is math (length, surface area, cross section, volume, and mass) to explain the Big Thing, Little Thing (BTLT) rule, but wait, there’s more! Flight, surface tension, walking on walls, strength, digestion, respiration, circulation, habitat, temperature, and migration, and communication all come into play. I recommend this book for everyone, especially those who can share it with nine to twelve year old children.

If this book sounds too serious, read it for the superhero debunking, giant spiders that break their legs, and whale guts.