I've just got a four month old female kitten and been trying to gradually introduce her to our 14 year old male cat. However, whenever she sees him she hisses, growls and then chases him. He doesn't seem to know how to react and ends up just running away from her. She can be really quite aggressive towards him. I'm not sure what to do about this and at the moment am trying to keep them apart most of the time. Any advice about how to help them get along would really be appreciated.