A friend told me that he stirs the mound and then sprays with pesticide. He does it several times and then spreads poison granules. His theory is that by reducing most of the workers, they are suckers for the poison and feed it to the queen. However, my bee keeping experience tells me that they can raise a new queen in a hurry.
Dave -
Your mileage will definitely improve if you leave the mound undisturbed before treating it. The queen will scoot right fast when it is disturbed and so if she survives you're just going to get a new mound elsewhere.
From
http://fireant.tamu.edu/controlmethods/ :
"These treatments are most effective when ants are nesting close to the mound surface (as they do when the temperature is mild). Colonies should not be disturbed during treatment."
