You can't really, but the good guys will recolonize the pile.

I've heard boiling water down the hole can kill a lot of them. This is a good nontoxic way that won't leave chemical residues that can harm other critters. There will be survivors but if you turn the pile and disturb them, they may move out. If not hit them with the boiling water again after a few days. Repeat as necessary.

You can search 'Fire Ants' in this forum for some discussions from other people who have dealt with them.

If you can stay away from them, they're not a bad thing in a compost pile. Ants in general, and fire ants in particular are fabulous excavators, and do a great job of aerating the pile. I believe they don't particularly like moist piles.

They like every pile that I have, and when it is time to put compost on vegetable's beds they relocate there and there and don't let my plants to grow normally. That is the main concern. When they come with compost to roses and other flower beds , that is not nice either.

I've read a lot about fighting with them on this website. And used every advice. It works several months, but then they adapt to everything. Even hi-yeild product did not work really well on them now.

I've read somewhere that the fire ants are not the ants family, they are belong to the wasp family. That makes me hate them even more, but probably I should use some wasp killing product soap or oil based. But that is working on contact and probably will not reach their queen.

As far as relocating them to the veggie beds - I've not had experience with fire ants, but have had surplus bugs in piles that aren't hot enough (but still compost). I put down a sheet of black plastic and dump my compost on that and spread it thin and leave it for a day or 2. The birds get most of the bugs and others find their way off the plastic as don't like being so exposed. Then I use the compost in the beds. (This is all un-scientific but works for me).

Fire ants are protein collectors and shy away from sweet treats. If you pour or spray molasses on the pile, it might send them away.

Fire ants are true ants. However, ants AND wasps, bees, hornets, and their ilk are all members of the same insect order: Hymenoptera. That makes them related, but with extensive differences.

Amdro is not "largely non toxic" it is toxic. Amdro kills its target, fire ants, and is slightly toxic to humans. You cannot, legally, apply Amdro to food crops for that reason. Putting Amdro on the compost that might end up around food crops would not be a good idea.

Pouring boiling water on any in ground insect home does nothing to kill the insect in that home since the soil would lower the temperature of the water long before it reached the nest.

Unless those ants are moving large amouints of compost off the pile I'd not get to concerned about them.

kimmq is kimmsr

I don't know about normal fire ants, but my mutants eat everything -sweet, protein, amdro, over'n out, etc and laugh and procreate even more.

As I said, Amdro has a very short lifetime in the field, so it's completely non-toxic when it isn't there anymore, which happens pretty fast. But the LD50 for Amdro is enormous. You have to consume huge quantities to risk death. By the same token, if you're trying to use Amdro that has been sitting on the shelf for a few years, it won't work, because it has degraded. The stuff works well, as long as it is reasonably fresh.

I sympathize with you though. Stirring a compost pile with a shovel or fork isn't pleasant if you have those ants crawling up your implement. Been there, done that.

I don't think the OP would care about them if they weren't trying to turn or use the pile. I sure wouldn't want them coming at me, yikes. At some point you have to deal with them or you never get to use your compost. Here in MO we got ticks and chiggers, I can't imagine life with those PLUS fire ants.

Amdro (hydramethylnon) is pretty effective ant stuff. For better or worse, I worked on the env. fate studies for it in the early 90s when American Home Products was a client of our lab. Interesting historical note: that was right after they changed their name from American Cyanamid. The days of advertising 'better living through chemistry' by companies with toxic sounding names were coming to an end. After Love Canal no one did that well with names like United Sulfur & Stench Corp. or Consolidated Carbolic Corrosives. LOL In any case, moderation in all things, so if you use it, SPRINKLE the bait and don't dump. Or better yet use plastic bait stations. I don't think it would become a problem in the average garden unless you used way too much for the job.

This puts me in mind of doyourownpestcontrol.com which has specific products for various kinds of ants. I had carpenter ants chewing the Styrofoam insulation out of a brand new garage door a couple years ago, got some gel specifically formulated for them from those guys and it worked like a charm. I only used about 10% of the syringe full that I bought too. It doesn't take much if you have the right product.

Today I've turned my recent wood chips based pile. Last time I turned it I added oak leaves, UCG, and some kitchen scrap, not significant amount at all compare to volume of wood chips. As a result, I've got very strong alcohol smell. I don't know what cause of that came first- the pile produces moonshine and attracts fire ants, or the fire ants make spirits aka firewater.

Pyrethrum is used for wasp infestations. It is the most commonly used organic insecticide around the world. Thankfully I don't have to deal with fire ants but it should work on them as well as it does on wasps.