|MadSci Network: Zoology|
Cats meow when they need attention. Nope, nope,.... I mean when they DEMAND attention! Have you noticed that they don't always need it, but ask for it anyway?
Purring is most important in communication between a mother and her kittens. It is a sound that does not carry too far and therefore does not alert other animals that may be a threat to the kittens. Kittens are able to purr and take milk from their mother at the same time, which communicates to the mother that everything is OK. The mother also purrs to send the same message to her young while they are feeding.
Purring may also be used to communicate peaceful intentions and satisfaction with the present company. If a cat purrs in your presence, then it is saying that it is comfortable to be with you. Purring is also used in a variety of other situations, sometimes even in its moment of death.
If you would like to know more about cat communication then I would highly recommend Catwatching by Desmond Morris. Your public library ought to be able to get hold of a copy. The book answers many frequently asked questions about a cat's behaviour. Although the book was not written specifically for your age, it has been written to appeal to as many people as possible and I think you will be able to make use of it.
Also, see Kelle en Flaherty's Answer To Purring.
Try the links in the MadSci Library for more information on Zoology.