Here are some interesting ideas for fire ant control in the back yard:
From Dale Barnard:
I had billions of fire ants throughout a compost pile and tried all the liquids mentioned, from boiling water to mixes of molasses and citrus oil and compost tea, but nothing worked well enough to get them out of the pile. Then, I realized that fire ants always build their mounds or caverns in open spaces, usually exposed to the sun. I covered my entire compost pile with cardboard to block the sun, left on vacation for a few days, and when I got back, the ants had entirely moved on.
It didn’t kill the ants, just got them to move out of my compost pile, but the nearby mounds that popped up were easy enough to control with the suggested boiling water and/or solutions.These days, I just use cardboard covers to move the ants or a spinosad-based bait to kill them, which is pretty close to an organic solution that works super well. It’s so much easier than boiling gallons of water and transporting it to the piles or mixing up expensive solutions. One more tip is to store a spinosad-based bait in a cool environment, not in the garden shed. In a garden shed, it’ll last a summer, but the ants will ignore it by the next summer. Kept under a kitchen sink, it seems to have lasted into a second summer.
and Janet Giles responded:
A way that always works for me is to take a shovel full of ants from one mound, and dump it on the other one. Then take a shovelful from it, and dump on the first one.
Next day, no ants. Where they went, nobody knows. Occasionally I have had to repeat one time.