[原創] dog

When a dog follows its nose, it's actually being led by thee key senses.Sight:a glimpse of the enemy saves them barking up the wrong tree. Sound: a bark can be a fierce threat, but it's also how canines make their long distance calls. Smell: this tells a dog more than all the other senses put together. Inside its nose are around two hundred million smell sensitive cells, forty times more than in humans. Through them the dog's brain can pick up signals from one molecule of scent in a million.