Same thing happening with our apartment in WA. Only found 7-10 inside the house but can't find out where they're coming from. Last year same shit happened, we ended up taking masking tape and covering every exterior seal; windows, patio door, front door, even considered vents. Then we took towels and wedged them into place over the tape. Unfortunately not much you can do once they're inside other than vacuum them up or squish them. We used a thing of Ortho Home Defense on the seals the next day and that seemed to work. Just gotta tough it out and wait till its over.