I've got a third story apartment as well, but man.....this morning it got so bad, I had to actually blow up the stairs leading up here. I had a barricade set up at first, made out of chicken wire (because who lives in the suburbs and has barbed wire, I mean really?), and that, nailed to some planks of wood did me next to nothing when faced with those slavering hoardes of the unclean. They knocked it down, and then I knocked them all down, right down the stairs (after risking my right elbow). I then blew up the stairs with a crazy mixture of orange juice and c4. It worked nicely enough.