A friend of mine has to move and give away her two cats, Calli and Leo. Leo already has a home lined up, but they can't find one for Calli. I'm thinking of taking Calli off of their hands, but I already have two cats. They're both males. Pickle is 3, and Cooper just turned 2. Calli is a female just over a year old. Mine are fixed, and my friend will fix Calli before she moves out. I'm a little worried about introducing Calli and Cooper (I think Pickle will be fine with it after some time). The reason for my worries is that Cooper has gotten aggressive with Pickle in the past. A few times, when another (outdoor) cat is near our house and Cooper sees it, he seems to become POSSESSED, biting and clawing and chasing Pickle around the house. We have no idea why he does this, because Pickle and Cooper get along quite well. He hasn't done it in a long time, but I don't want him to attack Calli on sight. I figured it might be a territorial thing, or competition if the cat outside is a female. Another thing I'm worried about is if Calli will be satisfied staying inside. She was allowed outside at my friend's house, but she won't have that luxury if she moves in with me. There are a lot of predators around my house, in general. Not to mention that there are cars around. I don't want my cats to get hurt, so they stay inside. Will Calli be satisfied staying indoors if she was allowed outdoors for the past few months? If you have any advice for me, I'd really appreciate it. My friend is moving in less than a month.