In my land in Uthai Thani I have loads of fire ants. They have nests every where when we have water and they bite so painful. They build the nest in the leaves and one way we do to kill them is to cut of the branch and let it fall in water. Some time I put the three on fire to kill the ants but its difficult to make the leaves catch fire. I have not try any chemical yet but I guess its time soon.