Boric Acid works great on roaches. That’s all I use.
I hate fire ants. I keep kerosene for those sobs, works great for a fast kill including their eggs if they’re at the top. I dig them up and pour away.
Just don’t use it anywhere you want a plant to grow. Sometimes I think they know that because they like to get in my big flower pots.
Fortunately we don’t have fire ants but the kerosene sounds good. Thanks for that info.