Outdoor

I have a 2 year-old cat...that I found when he was 4 weeks old. He was found in a garage. For the past year or so he has been trying to get out of the house whenever someone opens the door. A few times he has succeded in doing so.
I am wondering if this is causing a problem with him. He is a bit aggressive with my boyfriend and I. For example, I am doing laundry when I open the door he wants to get out, when I come back in he will start biting my ankles. I am going to assume it is because I didnt let him out.
Is there anything I can to help the situation?
I live in a two-story apartment building so letting him come in and out is pretty much out of the question...

If he isn't neutered, that could be a major problem (never mind spraying all over the house). If he is, then maybe there are just other cats around that he can smell and want to chase off. I think looking into getting some Feliway would be a good idea for him - will help to calm him down.