9 week old bully!

We just got a new addition to our family. He is a nine week old little siamese boy. We already had one cat..a siamese girl who is one year. We took our time introducing them..kept them seprated for 4 days...slowly let them spend supervised time together..etc. We were assuming that our older cat would be agressive to the new kitten, turns out the new kitten is a real bully. He puffs out and hisses and chases our little girl all around the house. They have seperate litter boxes and food and water dishes..but he is intent on using her litter box and eating her food..right in front of her!!! She just sits back and watches in amazement. Any suggestions on how to deal with our little bully? How do I get him to eat his kitten food when all he wants is the adult stuff?
thanks

I hate to break it to you, but the kitten is not trying to use her stuff on purpose. The food dishes and litter box already have a scent to them. He is doing what he is supposed to. The kitten is puffing up and such to protect himself. They have not been together long enough for him to make a definate decision. You will probably see this behavior for a week to 2 weeks while he is getting used to his new home. With 2 cats in the house, it is impossible to make them use seperate boxes. With the food, the only way to keep him out of the adult food is to feed them in seperate rooms. I might suggest while he is still growing and needing the kitten food, to mix adult and kitten. This way you don't have to seperate them and both I am sure will be fine with it.

De ja vue!! When we got our kitten, she was 8 weeks old and just a fluff ball. When she was introduced to our 7 year old male (who is 15 lbs, and huge) she immediately growled at him, and he backed off. Appropriately, we named her T.C (Tough Chick). NOTHING has ever made our male cat back down, not even big dogs.

She ate his food, slept in his bed, played with his toys, you name it, she did it. He, being the gentleman (as my husband puts it) let her. Eating was a challenge, as they would switch bowls mid-way and eat each others food. Seeing that kitten food is high in fat, and Nigel (the older cat) was on a strict diet, he gained three pounds, and she didn't. The dry food is in a shared bowl, and she always pushed him out when she wanted to eat. He just sat back.

Now that she is full grown, he doesn't let her do any of the above stuff anymore. I think that he knew she was a baby, and let her have her way. Now they eat the same food and seem to know that he is in charge. We let them battle it out in the beginning, as that's how they determine it amongst themselves anyway. As long as there is no blood shed, it's okay. We can definitely see a ranking order now.

Give it time, and they will work it out between themselves. If there is bloodshed and obvious fighting, not just tussling, you will need to separate them and supervise their visits until they are at least cordial.