ME TOO! I usually find one or two in the plants in the house. We get Box Elder beetles too, and two varieties of ants. I swear we built on top of a gigantic ant mound. They are seasonal too.
But the stink bugs are numerous in the yard. The wife wants to 'nuke the yard' to kill the ants, and various beetles, but that literally does 'nuke' the yard, and kills darn near everything else. Diatomaceous powder does seem to work to keep them out of the house, but the ants don't seem to be effected at all by it.
I was told that all of them nest in the attic, and the walls. They overwinter in the heat trapped in the walls, and often come inside to feed. Spring time tends to draw them out, and then they lay their eggs in the walls, and later their offspring end up going out both ways. I was told if I really wanted to 'nuke them', I would strip all the siding off and replace the insulation, and also all the insulation in the attic. NOT CHEAP! WAY NOT CHEAP! Good luck with your struggles... (Smashing them isn't pleasant, for sure...)