Most of the crickets we are seeing now are field crickets (Gryllus assimilis). Late summer is mating time for crickets, so that can explain their congregating. As to why there are so many, we had a mild winter which did not kill any eggs. We also had a relatively mild, wet summer which provided plant growth. The plant growth gives them great hiding places and as the plants die, a great food source.
To keep insects from coming into the house there are a few things you can do. If there are any large cracks around the base of the home, these should be sealed. Install a lower door seal if your door has a gap at the bottom. In addition, you can apply a perimeter treatment of an insecticide, such as a permethrin. For the outside of the home, use an insecticide that is labeled for outdoor home insect control or indoor/outdoor. Whether you are using a pre-diluted product or a concentrate, be sure to follow the label instructions.
This article was contributed to by OSU Horticulture Extension Educator, George Driever.