It took several years but my neighbors and I managed to eradicate every fire ant mound on our properties. Virtually no fire ants for almost ten years. Unfortunately, my next door neighbor passed away and the fire ants retook control of his property. After the rains last weekend, I counted over a dozen new mounds on my property and that was based on a quick walk around. I know what I will be doing this weekend.
I have found the most effective way to control them is to pour Ortho Orthene directly on each mound whenever you find one and regularly broadcast Amdro all over your property.
Ping.
It is possible to keep them under control but it is a never ending battle and eventually you will lose.
Ortho also makes a (non-smelly) broadcast treatment, in addition to their (smelly) Orthene spot treatment. That combo seems to work well, too.
Just 1/4 teaspoon of Amdro on the biggest mound wipes it out overnight. Might not even take that much.
I get huge mounds 4 feet around in the orange grove sometimes, if I haven’t walked the orchard in a while. Sometimes there will be a big one at the base of a palm, but no matter how big the mound a tiny bit of Amdro takes care of it. We usually have a couple small mounds to do every few weeks, but that’s all on several acres, and seldom any near the house because the chickens or ducks must eat them.
Squirting dawn dish soap into the main opening probably would work too,though mostly against the worker ants, not neccesarily the queen. It seems like the fire ants take the amdro as if it is a prized gourmet treat directly to the queen, so it is very efficient.