You can understand a lot about your canine companion from his dog tail signs. That wagging or thumping on the carpet? You know your pup is feeling great. That feeling of dread when you walk through the front door and that same tail is tucked low? That tail tells you something has been destroyed by a bored pup while you were away. Whether you consider yourself fluent in wag or you're still learning how to decode dog tail language, read on to learn more about how your pet communicates.

A dog's tail originally evolved to help him stay balanced, like a tightrope walker's pole. It serves as a counterweight to the front part of his body when he's making a high-speed turn while hunting and helps keep him from falling off narrow walkways.
Now that a dog hunt generally involves finding the last piece of kibble that fell behind the bowl, that wagging tail is largely thought of as a communication device. Here are five key things the placement of a dog's tail can tell you, according to the Center for Shelter Dogs at Tufts University Cummings School of Veterinary Medicine.