There are several species of bugs that congregate this time of year so it is a little difficult to tell from your photo what species you are having problems with. You can send additional close up pictures or take specimens to the Baker extension office for a precise identification.
One species that has been a growing problem in recent years in your area is the grass bug. Large populations build up in the late summer and fall, and the adults look for overwintering for sites.
There are not many effective options for eliminating them as they breed across a wide range of plants and across large areas. To keep them out of your house , make sure to close up any gaps in doorways or windows. You can spray a residual insecticide around the outside door to help keep individuals from coming inside when the doors are opened.
This article gives some more information on grass bugs and dealing with them: