Lol Classic.
I don't even mean to exploit them. Standing in the corners allows me to throw molotovs, grenades, etc.; down, it gives me the best angle on the zombies, and I can see two sides of my base instead of one. It's not my fault the zombies want to play House of Cards in the meanwhile. Lol Or perhaps they are measuring their hierarchies. "Jim, no, get off, no Jim, you stay on the bottom, you're cannon fodder. Francine, you go to the top, you're important, as am I, now get off, I deserve that spot. Everyone else, carry us during this blood moon horde." XD