A look at why animals need to be the size they are - part of the six book series about natural biology which started with Poo and now includes Extreme Animals and What's Eating You? Have you ever wondered why animals are the size they are? Why some animals are big, why some are wide, why some are small and others are long and thin? Find out in this informative and wittily illustrated natural history book that explains all about how animals fit in to their environment and why, big, wide, small, long or thin, they are all just the right size.