If you dig down into the soil of a garden, you'll probably find hundreds of wet, slimy earthworms wiggling below the surface Despite their creepy appearance, earthworms are one of the most important animals in the world. They help plants grow by bringing air, water, and rich nutrients into the soil. These are just some of the fascinating facts children will discover as they explore the world of these soft, squirmy creatures. Vivid, eye-popping photos...