Join Cogz the Robot Dog and discover how DIGGERS, BULLDOZERS, and other BIG machines work! Cogz, and his mice sidekicks, Nutty and Bolt, are at a building site, looking at all the different parts of a digger. But how do they work? Discover all about hydraulics, learn about tractors and the jobs they can do, find out about the biggest machines ever made, and much more! Covering key STEM themes of engineering , physics , and inventions , and with a fun quiz to test your knowledge, this book will get your child engaged and hands-on with learning. Diggers Tractors Cranes Road Rollers Bulldozers Excavators Robot Diggers Perfect for vehicle-mad pre-schoolers , the Clever Cogz series lets you discover different vehicles, from space rockets to racing cars. Bite-sized text and colourful, informative illustrations introduce the transport topics in a simple , engaging way for young readers with a passion for machines .