When it started getting cold they started coming in by the swarm through any spaces between my AC unit and my window they could find (obviously ones I couldn't see). I spent about a week putting them outside one by one (I tried gathering a bunch to flush at once, but they defy fucking breathing rules and a few managed to climb back up out of the toilet), with like 3/4 showing up each day, then I finally gave in and moved everything from my window to try to get them all out and remove my AC unit (since I wasn't using it anymore anyways)... and then it took a week and a half for me to spot all the others that had wormed their fat asses in. And even now I'm spotting about one a week that makes it inside one way or another (now that the window's sealed again I suppose they're coming in other ways). I hate the sight of them, they're stupid and they can't even fly right (always waving side to side and flying right into shit) and jdhdglasg I fucking hate those things.
But yeah, they're called stink bugs, best thing is to catch them and put them outside.