Small bugs coming inside from closed windows at night; spray solutions?
Unlessyou seal your house in vacuum wrap this is an on-going issue in the summer in most areas. Even here in Colorado where the dry air keeps the bug population low, it's a problem.
As you suggested and I have found that a preventive spray is the most effective solution. I don't like using chemicals unless it's a last resort and I don't want to endorse a specific product but I have had very good success with a home defense perimeter spray. There are several out there. I spray it all around the exterior foundation, window frames and anywhere else insects might enter. Although they claim it's safe for interior application I personally only use it outside.
I only do it once a year in the spring and it lasts all year but your experience might be different.