Boxelder Bugs don't need to be treated with a pesticide, even with soapy water, and they are drawn to sheltered places for overwintering. Denying them access to nooks and crannies is the simplest and most effective way to discourage them from getting inside. This means looking for access points like worn-down door or window weather-stripping, torn window screening, or any gaps/cracks around vent covers or pipe/electrical entry points that could be better sealed. Granted, there may be areas too high to reach that they could be using to get inside, but little can be done about that other than to look for any corresponding indoor access points that could be sealed to keep any moving through the wall from actually getting into the home's interior. Fortunately, they are merely a nuisance indoors, since they don't bite people, feed on houseplants, or cause any structural damage. There is no type of repellent or other product used outside that would effectively keep them from congregating on a building wall or making their way inside if they have points of access, which is why management efforts focus on exclusion instead, so they are forced to find other sources of winter shelter. Since they are fond of Boxelder Trees (a native species of maple common to damp soil habitats), removal of any Boxelder trees close to a house might help to reduce their numbers, but should be a last resort given the other benefits mature native trees provide.

Miri

Miri,

You're welcome.