Fighting vs. Playing

My wife and I have a 1 1/2 year old cat, and just got a 9 week old kitten a few days ago and have brought her home. For the past two days our kitten has been hiding under our bed, and I understand that is natural as she becomes accustomed to her new home. But she has recently been coming out and exploring more and more, and our older kitten will continuously chase her down the hall or sometimes playfully paw at her. However, our new kitten seems to dislike this and every chase or interaction between them always ends in our kitten hissing, and running away to hide under the bed. She also will begin to hiss and even growl when our older cat tries to go under the bed with her. Now, both me and my wife thought they were obviously fighting, BUT on several occassions we have tried to shut our older cat in our spare bedroom (don't worry, with his water, food, and litter box) for an hour or so to allow our kitten to explore the house free from harassment. However, as soon as we put our older cat in the room and shut the door, our kitten begins to meow and wine, and scratch at the door to the room, as if she wants him to come out. So it almost seems as though they are playing. But there is a lot of hissing and growling, and our kitten seems confined under the bed because that is where she always runs to. So I'm not sure what the deal is. If you're still reading this, please lend some help. THANKS!

To be honest, the interaction you are describing sounds pretty normal. In all likelihood, your cat and your kitty are just in the process of working things out.

If you watch closely over the next few days, you may well see that your kitty is instigating some of the "fighting".

We brought home a second kitty a couple of weeks after the first. The first kitty was relentlessly aggressive for days, just constantly chasing the new kitty. Then, one day, I noticed they were both curled up sleeping together under the second kitty's hiding place bed. The next day, I saw the new kitty clearly instigating the chase and attack play.

Try sprinkling both cats with cornstarch baby powder and rub it in their coats. Or a dab of vanilla extract on their chin and base of tail.

In both of the above, its to make the cats smell the same to each other. You can also get some of the Feliway that helps reduce the stress with new cats. Some cats may take months to adjust.