The human senses pale in comparison with those of dogs. They can hear sounds at greater distances and wider frequencies; their noses are more sensitive; they have better peripheral vision and their whiskers can pick up subtle changes in air pressure. It is no surprise then that your dog will often race to the door long before you notice that someone is coming. "What Your Dog Knows" explores the fascinating world of canine cognition. It examines the five basic senses and presents a dog's-eye view of the world, helping you to understand and communicate with your own pooch, and presents practical tests and activities that will help you gauge and even boost your dog's intelligence. It also considers a question familiar to owners of the most intelligent dogs: does your dog have a sixth sense?