There is no such thing as "killing" fire ants. It's a myth. Do not be taken in by the myth. You only relocate the ants. They move over to the neighbors, the neighbors then relocate them back to you, and so on. So if you have them IN your trailer, any kind of ant spray will get those, but if you are talking about the mounds, the Amdro works okay to relocate them for a while. I've also had some amount of luck with the Ortho powder that stinks like anything. I wish you luck with your relocation attempts, and curse the person who introduced the fire ant to American soil.
Ed and Sharon
2010 Wildcat 28RKBS
2019 Ford F-250 XLT - AWESOME Truck!
Retired AF MSgt
I thought I was wrong once, but I was wrong!