When I was a kid we had a patio area made of big flat flag stones. Some red harvester ants (not the same as fire ants) moved in under one of the stones, set up a happy colony, and would attack anybody who tried to sit around on the patio. I wiped them out by dribbling a basketball on their rock. They swarmed out from under the rock and tried attacking the ball and they got smashed by the hundreds. I did that several times, and in a week or so I had wiped them all out. We sure knew how to have fun back in those days!
