What your cat's trying to tell you
Can you hear me?
A cat's ears are uniquely mobile. They can move their ears in almost any direction they want. With all that flexibility, cats' ears can communicate as loudly as a dog's tail. If your cat is relaxed and letting her guard down, the ears are more forward and tilted a bit to the side. The more anxious your cat gets the flatter and more back their ears get. And when one ear is flat while the other is up? That's just tabby trying to figure out what to do next.
Don't look into my eyes
Do you ever notice how cats seem to gravitate to the one person in the room who isn't a cat person? The person who isn't making eye contact? That's because in the cat world, eye contact can be a sign of confrontation. So if a cat appears to be staring you down, you might want to look away. Pupils can also say a lot about tabby's mood. Dilated pupils can signal everything from excitement to fear, and narrowed pupils can mean that she's upset or irritable (or just sitting in bright sunshine!).
Tale of the tail
Just because the ears can tell you a lot about a cat's general mood, that doesn't mean the tail doesn't have something to say as well. A quivering tail means a cat is happy to have you around, while a tail between her legs mean she's being submissive. If your cat's tail is sticking straight up - you have yourself a happy cat, and if it bristles, watch out - because she's feeling a little angry.
Full body language
We've all seen how unique each cat's personality can be. Some cats are naturally shy, and take a while to warm up to new people and experiences. If you have a cat that's not a natural social butterfly, just the simple act of having people over for dinner can be quite traumatic, especially if there are small children around who may not know proper cat handling etiquette.
In these types of situations, it may be best just to keep your cat safe in a bedroom, since she'd probably end up there anyway. At least this way it won't be because of a tail pull from a three year old, or a supersonic cackle from a loud aunt.
So many reasons to hide
How many times have you seen a cat crouching down with her hair raised, making her look much bigger than she really is? That means your cat is afraid, and feeling aggressive, as opposed to a more submissive cat that tries to appear smaller, and less of a threat. She may even go down on one side to show you that she's in a jovial and friendly mood. But unlike dogs, a cat rolled onto his back can still be upset. She might not want a fight, but if provoked she can still attack with her claws.
These are just a few of the many and sometimes-subtle gestures that cats make to express their moods. Knowing your cat better can also help prevent unwanted behaviours like shredding furniture and aggression. It may take some time before you really know what your cat is trying to tell you, but once you have a better idea - you'll both be happier.