On a similar note, a friend called me a couple weeks ago regarding a bunch of tiny ants falling from his ceiling. There also seemed to be thousands out behind his siding. He was a biologist for CALTRANS prior to retiring. I recommended a pest guy who confirmed they were not termites, but didn't know what they were. Finally found out they were Booklice, also called psocids. Pretty much harmless. Now they are all gone for some reason.