What are you saying, kitty?
Here are the ways that cats communicate:
They naturally meow just as kittens to get their mother's attention. But as a result of domestication, it appears that they have learned to meow at humans for the same reason!
Most of the time, cats purr because they are happy. They sometimes purr when they are feeling sick or during stressful moments.
Cats hiss or growl when they are angry or want to threaten other animals or humans. They typically will attack with their claws and paws if whoever they are hissing at doesn't back off.
This is a "bird-like" noise that cats can make while watching potential prey. Some have thought that the cats are imitating birds or mice, but the accepted theory is actually that they are simulating the biting motions they'd do if they actually caught the prey.
Cats make this "crying baby" or howling noise to signal to other cats that they are in heat. In rarer occasions, cats will caterwaul to get their owner's attention, like if they are behind a door and need to be loud.
6. Body Language
There are so many ways cats use their body to communicate, I feel as though it may be their primary source of communicating, especially with other cats, who instinctively know what their bodies are saying. Here are a few examples, some of which could be confusing to humans:
- Lying on their back: this could mean submission and trust, or that they want to attack with all four claws, or just that's how they feel comfortable
- Puffed tail: the cat is surprised or scared; they can also arch their backs and puff out their back hair to look bigger to whatever they feel threatened by
- Tail-twitching: this could mean they are hunting, or they are irritated, or they are excited, or they are playing
- Flattened ears: the cat is feeling threatened
- Nose-touching: this could just be a friendly greeting, or they are marking their territory
- Licking: the cat is trying to bond with another cat or sometimes with their human owner
- Pawing: this could mean they are showing affection or contentment or curiosity, or that they are comforting themselves, or that they are marking their territory
There are tons of other ways cats communicate to each other by whisker position, tail height, and other body movements.
Cats claim territory by territorial marking or by rubbing their scent on people or objects.
All that to say (since it seems I have strayed from the original question): it appears that past kitten-hood, cats mainly meow to humans, and use a variety of other methods of communication to deal with other cats and other animals.
It's pretty smart of them, actually. Cats must have figured out at some point that humans communicate well with noise... and don't always read their body movements correctly!
ps. Check out this cat who somehow learned to bark... yet didn't want their human owner know! I guess cats have a great ability to learn how to communicate the most effectively.