If you use a targeted ant bait, the ants will take most if not all of it back to the nest and consume it. I figure you use so very little to gain so much, especially with fire ants!
Our local County Extension released a parasitic wasp that is helping a lot with fire ant control around here. Maybe ask your County Extension about this?
There are insecticides that use Spinosad which is organically acceptable since it does not persist in the environment, but is broken down by natural soil processes.
http://www.2ndchance.info/flea... I talked yesterday to someone who used a Spinosad powder to make an ant bait. Don't know how well it works, though.
The other way to go is DE, diatomaceous earth. You can try spreading it around the ant mounds and see if it helps. It will certainly kill some of the ants in a completely non-toxic manner, but it may actually cause the nests to 'bud' or divide and spread around, eventually making the problem more widespread.