I have ants occasionally in the summer come through the cracks in my garage floor. What is the best way to eliminate them?

  • possible duplicate of How can I get rid of ants in an environmently friendly way? Commented May 27, 2015 at 11:43
  • 2
    @RowlandShaw Nothing about "environmentally friendly" in this question.
    – Ecnerwal
    Commented May 27, 2015 at 12:30
  • I added "in my home" to the title, since asking about outside ant killing would have been a duplicate of this question: diy.stackexchange.com/questions/4831/…
    – Doresoom
    Commented May 27, 2015 at 13:36
  • @Ecnerwal Only one answer here is not potentially environmentally friendly (I'm unfamiliar with Terro), but all the other answers from both questions apply to both questions (including some identical answers relating to use of Borax) Commented May 27, 2015 at 14:12

5 Answers 5


Some options to consider:

  • ant poison (Terro a being a popular choice)
  • fill in the crack (concrete crack filler)
  • get a pet anteater (not sure how easy they are to house train)

Once the ants are gone, you can then get perimeter ant poison for your big-box DIY retailer. It's a granule that you can spread around the perimeter of your house to help prevent them from migrating into the house. Diatomaceous earth is also a good choice as a perimeter barrier (it's basically a sand that is microscopically 'sharp' for insects and they are reluctant to cross it).

  • Good advice. Poison first, then vacuum out your floor cracks and fill with either cement (larger cracks) or self-leveling polyurethane sealant. Commented Dec 10, 2012 at 4:45
  • I put food grade diatomaceous earth, as well as Niban fine granular bait (boric acid), around the cracks that ants have been coming out of the past few weeks. They seem to have had no effect on the ants as they are still coming and going through both of them. Obviously diatomaceous earth doesn't have an expiration date; not sure about the Niban - got it 7 years ago. Now I'm trying the Terro liquid bait. Commented Apr 8, 2023 at 5:40

My own (not) special blend of herbs and spices. Specifically,

1.5 cups warm-to-hot water (warm water mixes better) .5 cups sugar 1.5 tablespoons 20 Mule Team Borax

Mix vigorusly. The method of delivery I used was soaking a cotton ball in the mixture and placing the cotton ball on juice bottle top or something similar, and placing this in (a) strategic location(s). The sugar attracts them and the borax they can't digest, so poof.

Another bonus is it's recursive. My wife told me that ants will carry dead ants back to somewhere (their hq?) and eat them, since we've effectively poisoned these ants, the second round of ants will be poisoned when eating these dead ants as well. I've seen this in practice, although I'm not sure how long the cycle lasts.

Usually they're attracted to the trap for a couple of days or so before a new one is needed, not sure if it's because the path to that food is marked as bad, or because the cotton ball got hard or something else, so they can't smell the sugar. We've got them pretty bad so although these definitely work, they keep coming and I think it's because I haven't found where their entry point, thus why I'm scouring SE. Glad to see this is on topic, but I digress.

Oh yeah, credit where credit is due: I originally got the recipe from here.


They don't like to cross soap. I like to use dish soap to direct the ants to march around the kitchen like a Balanchine dance troupe.


I personally don't like to 'kill' ants. I'd rather 'keep them away' :)

I ain't an expert but here are a few things we do to keep our food safe from ants.

  1. If you have to keep cakes or the like, first use a plate with some water and place the container for the food in it. This way the ants cannot reach the food.

  2. Add a few cloves into the sugar jar but makes sure not to bury it in. Amazingly, the ants don't come to it for some time.

  3. Always keep food covered/sealed in containers whenever possible.


Note that the right answer depends on the type of ant. Exterminator told me that for the small "sugar ants", retail bait traps work as well as anything he could offer. For other varieties, a barrier of sticky poison the ants will walk through and carry back to the nest that way is preferred; pro products are better, and a pro's going to be somewhat better at figuring out what paths to protect. Carpenter ants, as I understand it, require finding and physically removing the nest, vacuuming up as many as possible of remaining ants, repairing the damaged wood, and then a pro-quality treatment.

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