by Pamela Sosnowski

Created on: January 18, 2009   Last Updated: January 27, 2009

Why do cats purr? It's a mystery that, remarkably, scientists haven't figured out yet.

For cat owners, the melodic humming sound that radiates from their feline's throat area usually occurs when the cat is happy. However, cats also purr when they're sick, scared, or stressed. Female cats will purr when giving birth. Mother cats purr to their kittens, and kittens purr when they nurse.

Furthermore, the loudness of purring varies from cat to cat and on the circumstances. Some cats purr so loudly their body shakes, and others are so quiet you can only tell they are purring by feeling their throat. The volume range of purring has actually been measured and can be between 25 and 150 Hertz.

Some experts believe purring is the feline equivalent of human meditation, and that when cats purr it can be likened to us repeating "Ommmm" while meditating. It may be a cat's secret weapon against stress.

Scientists also don't know exactly how cats purr. One study believes that cats activate the nerves of their voice box, causing the vocal cords to vibrate. Air is pushed in and out of the vibrating cords, creating the purring noise.

Whatever the reason and however they do it, purring is one of the ways cats communicate with humans and with each other. Their most common method of communicating is of course, meowing. If you've wondered what a cat is saying when he or she meows, they are quite simply talking!

There are several types of meows, and each one means something different. Just as humans change the pitch and tone of their language to indicate whether they are asking a question or making a statement, getting familiar with a cat's different meows can help you understand what they are trying to tell you, whether it's "I like you" or "Pay attention to me!"

When a cat is happy, his or her meows sound cheerful and pronounced. If they're insistent or repetitive, that means he or she wants something from you - such as food or to be let outside. Think of how whiny a child sounds when they ask their parents over and over again for something. And just as people moan when they're sick, in pain, or sad, cats can communicate that through their meows as well. A low-pitched or weak meow is usually a sign that something is wrong.

Some cats also make a chirping or thrilling sound that indicates that they are very happy. You may hear this noise when they're playing, enjoying catnip, or just extremely glad to see you.

Getting to know your cat's communication skills can strengthen the relationship between you and your pet.

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