How can I safely get rid of fire ant mounds in my backyard?

Question

I've got around 8-10 fire ant mounds in my backyard, and a puppy that has recently discovered a love for digging in them. We haven't let her out in the backyard unsupervised for the past week since the weather started warming up and the ants are now active.

I tried using Spectracide Fire Ant Killer Mound Destroyer a few days ago. It kind of worked. I followed the directions to the letter, and waited for the ensuing ant apocalypse. As of today when I checked on the ant mounds most of the ants were dead, but there were a few dozen survivors milling around when I poked a stick in half the mounds. The Spectracide claims to kill the entire colony and the queen in 24 hours. :/ Does anyone have a better product to recommend, or another method of killing them? I'd prefer something that's relatively pet-safe, since the ultimate goal is to let our dog roam free in the fenced backyard.

This is somewhat related to How can I get rid of ants in an environmently friendly way?, but I'm not too concerned about environmentally friendly. Just something that won't be hazardous to pets a week or so after it's applied.

Answer 1

If the product you used mostly worked, you may want to try a second application to wipe out the rest of the colony.

After doing some research there doesn't seem to be any tried and true solution to killing the ants (at least none I could find, I'm sure there are tricks exterminators use that they don't want to share), but most solutions seem to involve drowning the ants (in hot possibly soapy water).

You may want to contact your local pest control specialist, as I'm sure they have dealt with this problem before and no doubt have their own methods. Also having somebody else mess with the ants keeps you safely away from angry fire ants.

The least desirable solution I read about was to dig up the mounds, and "fling" the ants as far as you can. They did mention to make sure you fling the ants down-wind, but I wonder how many times they got a face full of ants before they came up with that little tip :).

Answer 2

I am a huge fan of Amdro. I find it works most of the time in a day. Every now and then I get a mound that needs a second application. I find good results if I don't mess with the mound and I hit them in the morning.

Having a pet I do spread some bait outside of his play area even when there are no mounds. I have even gone into my neighbors lot and hit their mounds (with permission). I try to get as large of perimeter as possible.

Answer 3

Boiling water is safe and works well.

Answer 4

Old question, but I’ve dealt with fire ants in every way imaginable—figured I’d share some battle-tested tips that might help other readers that come along.

1. Destroy the Colonies (Offense) Start by knocking out the existing nests. I use a slow-acting granular bait that fire ants carry back to the colony—it kills the queen and wipes out the nest from the inside. I prefer Maxforce Complete but have also had plenty of success with Amdro (note: both safe to use around children and pets when applied according to the product label instructions).

2. Build a Barrier (Defense) My go-to is cedar mulch around the yard’s border—it naturally repels ants and other pests, and it looks great too. It'll help to stop new fire ants from moving in. You can use insect-killing granules as an cheaper, easier alternaive. They kill on contact (not for nest elimination) so just around the border will do the trick. Sevin Insect Killer Granules or similar (note: safe to use around children and pets when applied according to the product label instructions).

3. Fix the Root Problem (Soil) This part isn’t for everyone—but I’m including it for the folks who really want a long-term solution. Fire ants love firm, sandy, well-drained soil because it holds the shape of their tunnels perfectly. If you improve your soil biology, they’ll leave on their own. There’s a saying: “If you have fire ants, you don’t have worms. And if you have worms, you don’t have fire ants.” It’s not just a clever phrase. It’s grounded in how soil ecosystems actually work.

What I do twice a year (early spring and mid-fall)

• Mow and rake/de-thatch thoroughly
• aerate (if necessary)
• Introduce Dutch white clover to lawn (improves nitrogen & repels ants)
• Inoculate with mycorrhizal fungi
• Top dress lawn with 1/4 to 1/2 inch of compost
• Water consistently to support soil microbes and worms

It might seem like a lot, but Steps 1 and 2 deliver quick results—Step 3 is what breaks the cycle for good. And as a bonus, your soil and grass gets healthier too.

Answer 5

Though I'd second the Amdro I'm a big fan of the Ortho Orthene.

It doesn't require watering in, and doesn't use much material at all. Though it can't be broadcast (so you can't do a whole yard) it'll usually wipe out a mound in a few hours.

Answer 6

Bayer make a terrific product called Top Choice. It is a one time application for year long Fire Ant control. It is a restricted use product so you licensed pest control professional will have to apply it if it is allowed on the label for your area. Spread rate is 84 lbs. per acre and may run around $300.00 an acre. Rate is 2 lbs. per 1,000 sq. ft. Re-Entry time is after application, but check the label. The label is the law!

The best time of year for an application is when daytime temps are around 75 degrees. First, it will kill fleas and ticks for the first month it's on the ground. And this is a peak time for fleas and tick activity. Secondly, it will be at its peak performance during the late spring when Fire Ant activty is peaking also with the spring rains. But, it can be applied anytime of year and will need watering to activate.

It should be noted that Fire Ants may still trail into your yard from surrounding areas. If they try to establish a mound in your yard, they will all die in about 3 days. It's not perfect, but I have been applying it for 6 years.

We applied it to a cities 34 acres of park lands due to heavy fire ant activity. The next year we only found 6 Fire Ant mounds. Best product I have used on Fire Ants in 23 years.

Answer 7

If you only saw a few dozen with that many mounds, I'd say it worked pretty well. I would walk the yard once a week and treat any new mounds. You can also do a broadcast spread. I like the Orthene powder. One spoonful kills a mound. Keep at it and evtually the fire ants will go to your neighbors yards.