So I just moved into my new house a couple of weeks ago and took in a stray kitten. Her name is stella. She's about 4 months old, very sweet and well behaved. A few days ago I took in an older cat from my brother. (By older I mean 3 or 4 years) her name is pixie. Pixie has lived with my mom and my brother, and has been bullied by their cats at both locations. I thought things would be ok because Stella is a kitten and even though she was here first, she hasn't been here for very long. When pixie and Stella met, things were ok. There was growling and hissing, but no attacking each other. They never got closer than a few feet from each other, and would just sit and stare from across the hall. They each have their own rooms with their own litter boxes, food and water, toys, and scratching boards. Last night, pixie attacked Stella while she was eating. I put her in her room for the night and she stayed in there all day. Tonight when I got home, I opened the door so pixie could come out and walk around. She came into our room and started using Stella's litter box. She also ate some of Stella's food. Then she attacked Stella, even though stella was just watching her. Stella has gone into pixies room and looked around, but she hasn't used her litter box or eaten her food or anything. She has not attacked pixie or provoked her in any way that I know of. I was worried about Stella attacking pixie because it seems that other cats just don't like her very much, but I guess it is pixie attacking Stella that I need to worry about. I love both cats and I don't want to have to pick one to keep locked up or get rid of, but I also don't want them to get hurt. What do i do?