When humans come to visit, they sometimes bring their own felines and canines too. I suppose they think that because they enjoy each other's company, that we should also be subjected to the company of others as well. Cats just simply don't think this way. We are very territorial, and know to respect the hierarchy of a family. The food chain goes as follows: Cat on top, then the humans that feed me, then the humans that don't feed me. The dog doesn't really factor into things, unless it tries to eat my food, and thus displays a death wish.
Now, when another cat is brought to visit, it by all rights should also be on the highest rung of the food chain. We establish a pecking order, I eat first (of course), then Tribble, then the guest. So the new feline understands this, I begin by venturing into the room where it's carrier is. This is the only piece of furniture in the house that I haven't either slept on or used as a means to get to another piece of furniture. Therefore, it is the only thing in the house that doesn't already smell like me. My first job is to claim it. There, now everything smells like me. For good measure, to show the new cat who's boss, I will sit by the supper can long after I am finished eating, until I am ready for my nap. This way, the cat will understand it's place in my home, and respect my authority like any good guest should.
Now, the dog is a different matter. You can't reason with a dog the way you can with a cat or even a human. The dog only really has two thought processes: "Oh good, my favourite!" and the far less exuberant "Oops, I just peed on the floor." Now, the latter has it's obvious down side. No one wants wet paws that smell like the filtering of last night's kibble. On the other hand, you have to be careful that you or your favourite places to sleep don't fall into the dog's first frame of mind. When a canine enters the home, it is full of unnecessary excitement. "Oh good, more humans, my favourite!", "Oh good, mini-humans' toys to chew on, my favourite!", "Oh good, a chair to sit on, my-" Now wait right there, buddy, this one is MINE."
A cat exudes it's authority by placing itself in a spot that prevents another animal from being there. Many cats have made the mistake of fuffing at a canine, and all that does is excites them to the point of insanity. "Oh good, a furry chew toy that wants to play AND makes noise, my favourite, favourite, favourite!" chomp. This fatal mistake never ends well for anyone. Instead, one must take an almost nonchalant approach with the dog. They expect a good chase. I say, don't give them one. In fact, if you want to really show them who's in charge, I say lie down and take a nap. Your humans love you enough to keep you safe, so why not let them do the work. This will drive the dog up the wall, especially if you sit in what it thinks should be it's favourite chair. So for now, I'll take a very unexcited stance on our guests, and remain at the top of your food chain. Speaking of food...feed me.