How To Deal With Unwanted Ants?

My TT picked up an infestation of Argentine ants (those very tiny black ants) a couple years ago. I tried the poisons and traps to no avail. Finally bought diatomaceous earth and threw it in the pass-thrus and under the sink and behind all the access panels, everywhere I could think of. That did the trick. It's safe to sprinkle around the tires and jacks when at a campsite, but you have to remember to reapply after a rain, as it loses its effectiveness after getting wet.