So why is that most four-legged animals have tails? Well, they might use them for balance when jumping or running. Flying squirrels and kangaroo rats use their tails as rudders. They can change direction in mid-air. Dogs use tails for communication. Some animals have "prehensile" tails, meaning they can grab things with their tail. Many monkeys can do this. Different animals use their tails for different reasons. A dog uses its tail to keep its nose warm when it sleeps, or to express themselves, like wagging it. A range animal like a horse or cow uses the tail to keep flies from biting them. A monkey uses it to balance itself in trees. A lizard uses it to fool other animals into grabbing the tail when they try to eat them. The tail breaks off and the lizard is able to run away.
Some of us are "tail impaired". Why? Probably because we don't need them! Bears, and hamsters are some of the animals with very small tails. Frogs, chimps and gorillas are with us in the no-tail category. But if you look at a picture of a human embryo that's under abut 7 weeks old, you will see that we all had tails at one point. We just lose them before we're born. We still have the tiny tailbones but they're not visible from the outside.
Check out the top ten animals with tails at: http://wonderopolis.org/wonder/why-dont-humans-have-tails/
What about that crazy curly pug tail? Pugs have curly tails due to breeding. A Pug's tail is set high, curled as tightly as possible, pinned to the back. Double scroll is more desirable among breeders. The tail is the way dogs express themselves, much like a flag. With a pug, if he is asleep and relaxed, the tail becomes long and loose. If the pug is happy, excited, etc. the tail is curled up tight like a knot on top of its butt. When a pug wags its tail, it will usually be tightly curled and flutter like a butterfly wing. When the tail is loose and wagging, in a circular motion, it is a submissive wag which is quickly followed by the pug showing you his belly. The only time Tootsie Roll's tail is straight is when she is sleeping...otherwise it is wound up tight!!
Tomorrow...Carnivore Two - Lucille the Yellow Lab!!