I have a significant portion of my back yard (1 acre) that is VERY sandy soil.

In that area, there are a lot of ants, and between the beginning of summer and the end of summer, they make so many ant mounds that it starts to crowd out the grass.

Is this a problem I CAN deal with? Secondly, is this a "problem" that I SHOULD deal with?

If I kill them off this year, will I have to do the same every year? If I kill off other insects too, will that make the ants come back more easily in following years?

If it's just the nature of having sandy soil and I have to live with it, that's fine. But if I can put down some ant killer pellets once and lower the population a decent amount (and if that would help), I'm down for trying. Just seems kind of strange to put down the pellets that say they'll kill all the insects in your yard, above and below the soil, when that kind of seems like the point of dirt. Does killing off the insects make it stagnant or something? As you can tell, I really have no idea what I'm talking about. Any advice greatly appreciated.

Note: it seems the only stuff I can easily get in bulk is the "kill everything" kind, not just ants.

  • 2
    Depending on the type of ants, if they don't bother you, it is okay to leave them alone, wood eating and biting ants, go and nuke them. Using general all insect killers usually kills insects you want around and not the best option. Would want ant specific and just knock them back instead of blanket killing.
    – crip659
    Apr 12, 2022 at 14:48
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    While your "kills everything" option might actually kill everything, it won't be for long. They'll move back in from the neighbors pretty quickly. Keeping insects down is a constant, ongoing battle. I wouldn't worry too much about having a long-term ecological impact from one application of insecticide.
    – FreeMan
    Apr 12, 2022 at 17:29
  • 3
    Should is subjective, and off topic here. Ants outweigh humans on the planet. You can wage war, to the detriment of the entire ecology of your yard, but you will not win.
    – isherwood
    Apr 12, 2022 at 18:17
  • 1
    In many places, ants deter termites. Apr 12, 2022 at 22:57
  • 1
    you can use boric acid to hit just/mostly the ants; super effective, non-toxic, and dirt cheap.
    – dandavis
    Apr 13, 2022 at 18:41

2 Answers 2


I have very sandy soil and thousands of ant mounds around the house just like you. Before I bought this house, a certified termite inspector found some carpenter ant carcasses in the house but no apparent damage. So I take steps to keep ants out of the house, but I don’t try to kill ants in the ground, because it’s not necessary and frankly impossible to kill them all.

Every year in the spring, I spray a stripe of insecticide on my concrete foundation (outdoors) completely around the house as a barrier. I use Spectracide Termite and Carpenter Ant Killer Concentrate (lambda cyhalothrin 0.5%) diluted with water according to package directions and applied with a tank sprayer. It’s available at big box hardware stores. This does not affect ants or any insects that stay in or on the ground, but if they crawl up my foundation, they will die.

The treatment lasts 8 weeks, when I repeat the application. The second application lasts until cool weather arrives and that’s all I need. In 8 years we’ve never found an ant in the house. The treatment works well without harming insect life that stays on their own territory.


Ants in your yard is where you want them to be. Better in your yard than in your home. You should make sure there’s nothing that can attract them to your building(s).

So, make sure there is no rotten or wet wood around the perimeter of the buildings on your property. Keep all wood fences and decks in good repair and replace any rot as soon as you notice it.

Ensure there is at least 8 inches between the top of the grade and any wood banding at the top of your foundation.

Basically you should be able to walk around all the buildings on your property and see a good clean gap of at least four feet between the exterior walls and anything that would attract the ants to the perimeter of the building. Don’t lean anything against the building that they could use to climb up to the siding or under the skirt board.

Clean up leaves promptly in the fall so there isn’t a bed of rotten leaves around the buildings.

If you do all of that, you’re not likely to have problems. If you’re really very concerned, you could hire a pest control company to inject poison around the perimeter of the foundation but that’s really not needed if you keep the perimeter clean and clear of debris.

Oh and make sure that you don’t have trees overhanging the buildings. They can also come in by falling on the roof from foliage that overhangs.

  • 3
    And brick houses may have vent gaps in the bottom course; be sure ants do not get into them. I have had ants and termites share the same mound at a vent space ( I know the "book" says that doesn't happen; remove and poison any mound at the foundation). Apr 12, 2022 at 19:30

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