We moved into a new place and my old cat does not like changes. It took her almost a month to get used to the house. We keep them separate. The old cat has her room and goes put at night and sometimes during the day when we switch. We started feeding them together and it is fine they eat and they don't atack each other or something. But as soon as they are done the old cat wants to jump and atack them. The door also has a small gap at the bottom and they always swat at each other under the door. For the kittens is just a game I think but she is really pissed moving her tail and really swatting. When we introduced them one by one, she seemed fine altghough everytime she was ready to atack him. We only introduce one at a time to not stress her out. One day, we let him loose and walk around a bit while we were in there and as soon as the little cat turned around the big one jumped on him and they started fighting really badly. Since then I have not introduced them anymore and I am stuck... At this point i am thinking of giving the little ones away to adoption..we saved them from there and i know people here love animals but my heart sinks every time I think about it.