There are small holes in my brick and these insects flying in and out. The look like miniature wasps--I would estimate 8mm long. What are they? Should I be concerned? They fly along the wall, trying every hole until they find one they can crawl into.
Thank you for the question, and for including your location and an image. They are solitary wasps called mason wasps, of which there are many species in your area. The females are looking for nooks and crannies where they can nest. The males are looking for the females. These wasps will flee rather than sting, and meanwhile they are killing many pest caterpillars in your yard and garden.