Fence preservative, auto carriage underbody early fall anti-rust, or, my own favorite, drenching the fire ant mounds I get from neighbors unconvinced by an all-organic program:
Drench mound thoroughly (after a quick dig in center with post-holer), soak thoroughly (about a quarter-gallon for our clay soil); wait ten minutes and light off with a touch of gasoline.
Sit and contemplate the screams, compare them to the many, many, many bites you had as a child. Much better than AMDRO and that other junk sold that rarely works.
Come back next day, dig it all up and send to dump. Or use as weed preventative along fenceline, house, if you have grasses that spread on and under soil as we do. A little, spread widely, goes a long way.
I send the rest to Walmart or county recycling center.