For years, every summer, we get streams of ants coming from behind our microwave. There appears to be no nest on the outer wall. Can they have a nest under the foundation or even in the walls?

Also, there are some bugs we've seen crawling through a hole near a window. Underneath that hole, there is a large pile of thin slivers. Not sure if it's pieces of chewed up drywall or what. They don't look like termites. They look exactly like ants. No wings.

Any ideas of how to get rid of these without a pest control person?