cellar spider home invasion
I agree with the vacuum. I would first suck up the spiders, then suck up a tablespoon of boric acid or DE. Then turn off the vacuum.
Another thought is to get a bottle of something similar to or equal to Home Defense. Spray it outside all around the foundation, windows, doors, vents, electrical and plumbing in areas, and overlaps of siding on the foundation.
I would spray the inside in the same areas prior to the final finishes. I would focus on corners and edges as well as the above list.