Did you know that cats purr for a number of reasons, not just because they are happy? I like to say that cats are “seeking contentment”. Cats do purr when they are happy but they also purr when they are afraid, in pain or are waiting for something to make them happy, such as attention or food. My cat Pookie became very ill very suddenly and I rushed him to the vet. He purred during the entire exam. I know that he wasn’t happy at that time. Two of my cats will purr when I try to put them in the cat carrier(which means we are going to the vet). I believe that they are fearful of what is to come.
Did you know that a cat has several means of marking its territory? Glands on a cat’s face and on the bottom of its paws emit pheromones that cause the cat to leave its scent. In many cases a cat is claiming something as its own. All of the door jambs in my house have been marked and remarked by my various cats. That is why you will often observe a cat rubbing its head against an object.
A kitten will knead its mother’s belly to stimulate milk release; later in life the adult cat will continue the kneading process. When doing so pheromones will be released. When a cat gets onto a person’s lap it will often knead for a while before lying down, the same for making a bed on a pillow, etc. Often Yella will smell my lap and knead vigorouly if another cat has been there before him. He is remarking his territory(and making my life uncomfortable).
Cats also mark territory by spraying their urine. Females in heat and feral males often do this. You can tell when a young female is in heat for the first time when she starts to spray.
One of the most common and annoying marking behaviors is when a cat scratches furniture. Every time Yella would come through the front door he would mark the living room by scratching a chair. I bought a scratching pad which he now heads for and uses instead. He is still marking his territory, but in a nondestructive way.