Soap on the ants works better than any other treatment. 20 mules I haven't
tried, just a drop of Dawn.  Gasoline will cover the ground water with a
film. Something like one cup to an acre.  It will stop plant roots from
tapping into that water.  There are questions as to build up under the
gasoline film on the ground water and the fungi and bacteria.  The film of
soften water from the borax may dissipate into the water to quickly.  Michael
Housel   Trying to raise Honeys without the chemical makeup.