Dogs talk with their tails, as they do with their eyes, mouth, and paws.

They're pretty articulate with their body language, as anybody who owns a dog can tell you. For example, when it comes to communicating with their tails, canines understand each other precisely. A tail sticking straight up means "I'm top dog here."  Tucking the tail means "you're the boss." But these universal signals are not so clear and precise when the "conversation" is dog-to-person. That's because centuries of breeding have muddled the animal's natural, inborn responses. The best we can say for sure about a dog wagging its tail when approaching a person is that Fido is excited.

Maybe its "You're home, now I can eat," or "I've been waiting to play, let's do it." It could even be what you want to hear: "I'm really crazy about you." But then again, maybe he's just saying "I have fleas."