Imagine an animal whose tongue can weigh as much as an elephant, and whose heart can weigh as much as a car. Blue whales are amazing animals that we have to weigh in tons, not pounds. This book explores the aquatic lives of the largest animals on Earth, from what they eat to where they live and just how big they really are. Through full-color photographs paired with accessible text, young readers will be amazed to learn that these massive animals survive by eating tiny plankton.