Using some thing like that Ortho Fire Ant Killer runs the risk of killing off a host of other beneficial insects in your yard, though. It's never a good idea to "nuke" your whole yard with a blanket treatment. You may see temporary relief, but in the long run if you kill off the beneficials, you may make the whole matter worse..
We had a wonderful entomologist, Dr. Fred Santana, at the Extension service here for years, and he used to give a 2hr. seminar on ants every year. It was the most popular class every year, and I took it twice before he retired because he was one of those guys that was just like a little kid when he started talking about bugs.
All the "instant kill" insecticides and things like boiling water don't really get rid of the ants, they most often just make them move and create another nest. The proven way to get rid of fire ants (and most other ants as well) is to find what bait they will take and keep putting out a little more bait until you no longer see any ants. Some ants will take a sweet bait like Terro, or the water/sugar/Boric acid home-made version. Other ants like a protein bait, and some ants change their diet from one season to the next. So you need to put out bait (a tiny sprinkle on a mound for fire ants) and stand there to see if they start picking it up. In general, fire ants don't take the sweet baits. They like a granular bait and the most effective one of those is Amdro. But it must be fresh! If you open a package of it and smell a rancid smell, take it back to where you bought it! Amdro is not an organic-approved bait though, but since it is a bait and you use it very sparingly, most of it is consumed by the ants and doesn't get out into the system. More is not better. A light sprinkle usually does the job well.
We had a product called Come 'n Get It recommended as an organic alternative bait to the standard Amdro bait. We're not allowed to use anything but organic pest controls at the school garden, and it worked well the first time we applied it, but unfortunately we got a second batch that was not fresh and the ants didn't take it. A couple of months into our school year, we started seeing ants again, and they weren't going away. So again, source it locally don't buy it online, and smell it as soon as you open it to make sure it's not rancid or it won't work.
We compromised by using Amdro outside the fence of the garden, and the ants went for it.
Never seen any birds taking that bait, but I like the idea of putting a box or bucket over the mound after you've treated it until the bait is all gone.
