We don’t typically advertise Eco Orange as a bug/ant killer, and we try to make a product that is family-friendly and safe and that may extend to bugs. That said, to repel them spray a mixture of 2 parts water to 1 part Eco around your home – the citrus fragrance of the d-Limonene, which is in Eco Orange, will repel the ants; and PETA will be very happy with you if you are merciful to the bugs.
Now to kill them, apply directly to the ants. D-Limonene is known to penetrate the respiratory system of bugs/ants causing them to suffocate.
Hope this helps in your quest to rid fire ants. They are pesky little buggers.