The best stuff for red ants was methyl chloroform sold as ant killer and in spray cans as brake cleaner. It was outlawed 1986 as an air pollutant, although the way it worked on ants was about an ounce at the top of the anthill penetrated all the way down. Since it was heavier than air, rocks, balls, and gliders could be classed as air pollutants, but don't tell the greenie weenies.