Book excerpt: Down where worms wriggle and microbes squirm, there's a whole world waiting to be discovered... Under Your Feet delves beneath the Earth's surface and explores the diverse wonders hidden there. Encounter creatures of the deep and marvel at the mind-boggling size of the humongous fungus - the biggest organism in the world. Learn how one handful of ordinary soil contains more organisms than there are people on Earth, and carry out experiments using dirt from your own back garden. Under Your Feet offers you the opportunity to expand your knowledge of the natural world and soil-dwelling creatures big and small. Bursting with colorful illustrations and photography, this is the perfect book for budding young plant experts, animal fanatics, and geologists, and anyone who is curious about the ground we walk on.