The saga with the ants and my shower continues. But now I have a new weapon in my arsenal, courtesy of Richard Knocker. Ants will not cross ash. After meeting the concept with skepticism it has proven to effective. I ringed my patio with ash from the fire place and it has created an inpenetrable ant barrier. I can't tell you why. Maybe they have evolved an aversion to burnt and burning areas. Maybe it hides their pheremone trails. Maybe they just don't like it. Whatever the reason, they will find any alternative path rather than cross ash.
Of course, rather than succeeding in keeping the ants out of my room, all I have managed to accomplish thus far is keeping them locked IN my room. And so the saga continues.