We recently got a new cat(lola) from the humane society. She is 4 years old, had two litters and is fixed. She is very sweet to us, slightly skiddish yet, but never agressive to us. The problem is our original cat(Miko), who is a 6 year old female, is terrified of the new cat. Miko refuses to go in the basement where the new cat is. We had to put a litter box upstairs for her because she wouldn't even go downstairs to go to the bathroom. When Miko sees the new cat she hisses and runs, so terrified she runs into doors and chairs. She'll even hiss at us if she smells the new cat on us. The new cat has slowly made her way upstairs, but gets frightened easily. Lola is very interested in Miko. She goes directly to her when she sees her, never hissing or pouncing, but she acts like she's going to attack Miko. Lola crouches and runs up to Miko when her back is turned, however she does not seem aggressive, just curious. None of us know why Miko is so terrified, or if Lola is actually trying to attack Miko. We recently had an old cat die back in May, don't know if that has anything to do with it. Please give us any advice or suggestions.