Compress the fire ant bites with ammonia liquid. The bites are shallow enough that if treated promptly, the reaction is milk or only 10%. (Your mileage may very). Best treatment I have found.
This also works for scorpions, yellow jackets and wasps, etc. These later stings bites are more persistent because the venom is injected deeper into the skin. Burt if only one or two of these deeper stings, keep the compress wetted and with a much longer duration
This treatment can make a high difference in stopping the creation of fire ant pustules and subsequent likely infections. (From constant scratching).
FYI.
Cheers
I’m in Alabama and garden a lot, and get fire ant stung a lot. Ammonia for me, too.
I keep a spray bottle of Windex on my tractor cart for this very purpose. As I drive around on my property I go out of my way to run over mounds.
I use Amdro bait to kill them. Works slow but kills the queen.