Fire Ants Suck... Here's How to Get Rid of Them

It's spring, which means Fire Ants are back in the South.

I've lived my entire life in Texas, so fire ants are a constant reality for me. To make matters worse, when my son was 18 months old, he had a severe allergic reaction to three fire ant bites in my garden, which resulted in a trip to the ER with an epi-pen injection along the way.

I have no mercy for fire ants, but I don't want to apply poison to the same yard my kids play in (or kill all the beneficial insects that live alongside the ants). So over the past several years, I've been experimenting with what environmentally-friendly methods I can find to treat the little devils. Here's my current arsenal of tools (scroll to the very bottom for a shortened version of the formulas):

Treating ant mounds in the yard

Create a "mound drench" of the following ingredients:

3 oz Orange Oil (aka d-Limonene)
A few squirts of liquid soap (dish soap)
3oz Molasses (optional, used to repel ants from recolonizing rather than kill them)
1 gallon water

Alternatively, Gardenville sells a pre-made mixture called Anti Fuego that you can get at a good garden store.

Mix all the ingredients together in something you can pour out of (I use a 2.5 gallon watering can). Quietly approach the mound, then slowly pour the mixture directly on to the middle of the mound.

The goal is to get it deep enough to reach the queen, but you should also spread it over the entire mound to kill the little devils trying to crawl up your leg. It takes about a minute to work. You'll notice the ants acting disturbed, then curling up to leave you in peace.

Don't worry about getting this stuff on your skin. It's not a mix you should bathe in, but I've never been bothered by it being on my hand for a few moments.

Orange Oil, the key ingredient in this formula, is a liquid insecticide that's safe to use around humans, animals and food. The d-Limonene in it instantly strips away the protective wax coating from the exoskeletons of insects, causing them to suffocate and die on contact.

It is effective against Ants, Roaches, Fleas, Palmettos, silverfish and many other crawling insects. Note that this will kill all insects its applied to, good or bad, so take care when applying it.

Credit to The Dirt Doctor, Howard Garrett, for the original recipe.

Treating ant mounds in the garden

While the mound drench is great, it will definitely kill plants. One time I unwittingly ruined my mint plant after I poured a full application on a particularly nasty ant mound making home in my planter (so much for the idea that mint deters ants).

As an alternative, mix liquid spinosad concentrate with water (read directions on label for specifics). It's pricey, but it's worked well for me, and doesn't kill plants.

Spinosad is an insecticide based on chemical compounds found in bacteria. It affects the nervous system of insects that eat or touch it. It causes their muscles to flex uncontrollably. This leads to paralysis and ultimately their death, typically within 1-2 days. It's not as instant as Orange Oil, but it also doesn't ruin your plants.

You do want to be more careful with it though. It's not for use near aquatic systems, and can be harmful to honeybee, so be careful applying it to flowering plants and wetlands.

Treating ants when the mound is missing

Sometimes you can't locate the mound, which makes it hard to apply our mound drench. I once had to treat ants that had made a nest in our walls and were climbing in to our kitchen via the electrical outlet.

In this case, I had to get a little creative and make a fire ant bait. While there are Spinosad-based baits out there, I haven't had much luck with them.

Instead, I make my own bait, based on a boric acid recipe. Most articles I've read out there say to use sugar water or peanut butter. Sugar water doesn't attract for fire ants and my son is deathly allergic to peanut butter, so both of those options are off the table.

Instead, cook some bacon, eat it, then pour the leftover grease in to a jar. Mix in 1/8 teaspoon of boric acid per 1/4 cup of grease (or 1/4 a teaspoon acid per half cup of grease).

Once thoroughly mixed, place the bait in a shallow container wherever you're finding ants. If you got the mixture right, they should swarm the grease.

Boric acid takes a little bit of time to work, and it's easy to mix too much acid in to where the ants won't want it. I'm still working on perfecting the recipe, but it has worked for me a few times already.

Also, it's worth noting that you probably shouldn't use boric acid in the garden, as it can be toxic to plants. Also, be sure pets/kids don't get in to the mixture, as it's not good for them either.

To Recap:

Mound drench (lawn):

3 oz Orange Oil
A few squirts of dish soap
3oz Molasses (optional)
1 gallon water

Mound drench (garden):

Liquid Spinosad mixed with water

Ant Bait:

1/4 teaspoon boric acid
1/2 cup fire ant bait (e.g. bacon grease)