DE is sold for ants & such (at very high prices compared to pool DE, check at any HD or Lowes). DE works (like Boric Acid powder, which is also sold to do the same thing) on bugs because it cuts through the exoskeleton and causes the critters to "bleed" to death. DE, though small, is very sharp, especially if you are very small.

Works great on carpenter ants. Drill holes where they are and spray in some DE or Boric Acid.