A cat tail is more than just a pretty appendage -- and it's more sensitive than you might think.

Nothing is quite as wonderful as walking into your home at the end of a long day and being greeted by your cats, cooing their happiness, their tails held high as if to say, “Welcome back! We missed you so much!” But your cat’s tail does much more than help you understand how she’s feeling. Read on for some cool facts about the cat tail and what it does.

First, let’s start with a quick anatomy lesson. A cat tail has 19 to 23 vertebrae, about 10 percent of the total number of bones in her body. An extensive group of muscles, ligaments, and tendons hold the tail together and provide its amazing mobility. The average cat tail length for a male is 11 inches, and for a female it’s 9.9 inches.

1. The cat tail is a balancing tool

The cat tail acts as a counterweight when the cat walks along narrow surfaces like fence tops or chair backs. It also helps a running cat to stay standing as he makes sharp turns in pursuit of prey … or his favorite toy.

2. It’s a communication aid, too

Cats communicate largely through body language, and the cat tail is one of the most important parts of your cat’s communication toolbox. By understanding “tail talk,” you can understand how your cat is feeling with just a glance.

A happy cat, for instance, walks with her tail held high, and a super-happy cat will add a quiver at the tail tip to demonstrate her joy. A mildly annoyed cat will twitch the end of her tail, but if she’s lashing her tail back and forth, you’d better step away, because the claws are about to come out. A cat concentrating on prey will have her tail held low to the ground, although there might be a very slight twitching at the end as she tries to control her excitement.

3. Cat tail injuries can cause permanent damage

Even though the spinal cord doesn’t extend all the way into the cat tail, an injury can still cause serious nerve damage. When the spinal cord ends, the nerves that help to control and provide sensation to the tail, hind legs, bladder, large intestine, and anus have to extend outward without the protection of the spine’s bones. Yanking on your cat’s tail can over-stretch or even tear these nerves and cause temporary (or permanent) inability to walk, inability to hold the tail upright, incontinence, or chronic pain.

4. Cats can live without tails

A cat whose tail is amputated because of injury learns to compensate for the loss pretty easily. Manx cats are born without tails, and I’ve never heard any reports of excessive clumsiness in these breeds.

5. Not all tailless cats have the same tailless gene

The gene that produces the unique tailless look of the Manx is dominant, which means it automatically expresses itself even with only one copy of the gene. Being homozygous for (having two copies of) the tailless gene is semilethal, and kittens with two tailless genes are usually spontaneously aborted, so tailless Manx cats are bred from one tailless parent and one tailed parent. But even having only one copy of the gene can cause a condition called Manx syndrome, which includes spina bifida, fused vertebrae, and bowel or bladder problems. The gene that causes the kinky, curly tail of the Japanese Bobtail, on the other hand, is recessive — a cat needs to have two copies of that gene for the trait to express itself — and doesn’t have the same potential for health problems as the Manx gene.