Why do dogs wag their tails?

Dogs use their tails just like we use our words to say how they're feelin'! Look at that golden pup up top—he's got a High Wag because he is SO excited to see you! When a tail goes swish-swash way up high, it's like the dog is shoutin' 'I'm HAPPY!' with his whole body. But look at the little beagle on the bed—he has a Hidden Tail tucked way under his tummy. He's feelin' a bit shy or scared, so he hides his tail to make himself feel small and safe. And check out the brave dog at the bottom with that Stiff Tail. His tail is pointin' straight out and not movin' at all because he's lookin' really closely at somethin' important! It's like his way of sayin' 'Shhh, I'm concentratin'.' Tiny Concepts.