I have a question Marla. You have multiple cats I see. How hard is it to introduce a new cat to an established one? Our cat is pretty nasty to other animals (like when our friends bring their dogs over) and he is pretty "aloof and territorial". If it comes down to it though, I will try introducing the two cats, but I don't know exactly what's the best way. Our cat is a neutered male, and this is a female.