How To Get Rid of Ants With Coffee Grounds

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Robert Pavlis

How do you get rid of ants? I have found that people use 3 common home remedies to get rid of ants; diatomaceous earth, Borax and coffee grounds. Borax does work and it is the main ingredient in many commercial products designed to get rid of ants. In this post I will look at the effectiveness of coffee grounds.

Getting Rid of Ants with Coffee Grounds
Getting Rid of Ants with Coffee Grounds, Photo Source: Charlie Stinchcomb

Why get rid of Ants?

Before I get into the main topic I would like to make a comment about ants. They are very good for the garden since they improve soil structure. Sometimes they build their nest right under a precious plant and that may cause a problem–but they rarely harm a plant. Ants are predators and eat other insects, so they keep bugs from eating your plants. For the most part their ant hills can be tolerated.

Ants in the home is a different story. I understand why you would want to get rid of them in the home.

But if they are in the garden, try to learn to live with them and leave them alone.

Ants and Coffee Grounds

You will find this advice all over the internet. If you want to get rid of ants, put coffee grounds on the ant hill and they will leave. Sounds simple enough. I searched the internet for some scientific evidence that coffee grounds actually work to get rid of ants and found none, so I decided to run some tests. My testing is not very scientific but it does give some insight into the issue.

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Ants, Coffee Grounds and the Shed

I built a garden shed about 8 years ago. Almost from day 1, ants took up residence in the shed. There is a space between the two header beams across the main 6 foot wide door. In this space they are well protected, and unfortunately, the way I built it, I can’t easily get at them. I never really tried to get rid of them–they don’t harm anything.

The common advice for using coffee grounds is to put them right on the ant hill, but these ants don’t have a hill. So I tried to put some into the space where they live, and I smeared coffee grounds along the trail they use for getting into and out of their nest. I then watched.

The ants sure don’t like coffee grounds. They would walk up to them, turn around and go back the way they came. That looked very promising, but would this be enough for them to leave the shed?

The next day I came back to see how things were progressing. The ants had pushed the coffee grounds off their path, and life was back to normal. I think I heard one of them squeek “that was a fun diversion for a few hours”.

Ants, Coffee Grounds and the Patio

I have a patio made out of rectangular man-made stones which are sitting on sand. From day 1, ants moved in and live under the stones. I found two entrances to their home, which were quite close together–probably led to the same nest.

One of the openings was just a hole between the stones. Ants were busily coming and going from the hole so I decided to surround the hole with quite a bit of coffee grounds, making a full circle. Ants the came out of the hole, walked up to the grounds, and then went back under ground. Ants arriving from distant lands went up to the coffee grounds, stopped, turned around and went away.

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The second entrance consisted of a hill of sand which the ants had excavated. Many ants were busy going and coming using this entrance. I covered the hill with coffee grounds, making sure some sat right in the entrance hole. Same as before, ants would not cross the coffee grounds.

Things looked very promising. Ants clearly do not like the grounds. It could be the smell, or it could be the particles themselves. I was dealing with small ants and the grounds were almost as tall as the ants.

Around noon the next day I returned to the ant hill. All was quiet–no ants. But then I noticed that ants at other untreated hills were also gone–WOW this stuff really works. I came back later in the day to check on things only to find that all the ants were out working again. I guess they took a lunch break during the hottest part of the day. Once things cooled down they were back.

What about the covered ant hill? They had removed almost all of the grounds from the hill and they were back in business. They did abandon the hole that was surrounded with grounds, and made a new entrance almost beside it.

How to get rid of ants with coffee grounds
Ant hill surrounded with coffee grounds

 

getting rid of ants with coffee grounds
Ant hill with coffee grounds the next day

Ants, Coffee Grounds and Precious Plants

I have a new rock garden full of very small plants and I look at it almost every day. Suddenly one day, one of my prized possessions looked like it was dying. I gave the plant a flick of the finger, and a bunch of ants came scurrying out. They were building a nest right under the plant, and since the plant was only 2 inches wide, they were doing quite a bit of damage.

I ran for the coffee grounds and spread them thickly around the plant. By this time I did not have too much confidence in the stuff, so I also got some Borax + sugar, and shook it over the plant itself. By the next day the ants were gone.

I don’t know if it was the coffee grounds or the Borax, which does work, but not that quickly or maybe it was my fingers shaking the plant. It is very likely that the ants were just starting to build their nest and decided to go somewhere else which was less hostile.

Coffee Grounds Tested for Ant Control

Dr. Wizzie Brown, an entomologist at Texas AgriLife Extension, also tested coffee ground on fire ants, and found they had no effect. Brown said, “spreading one cup of used coffee grounds over a fire ant mound failed to kill the fire ants. The amount of activity after applying the grounds was the same as on the control mounds receiving no treatment.”

Ants and Coffee Grounds–Conclusion

It is clear that ants do not like coffee grounds, but they don’t seem to mind the coffee itself. When I was applying the grounds some of the coffee also spilled onto the patio stones and they just walked all over it. I also don’t think it is the smell since ants walk right up to the grounds, before turning back. If the smell bothered them, they would turn around sooner.

I suspect that the grounds are just very large in comparison to their size–they are a physical obstacle for the ant. Keep in mind my tests were done with small ants. There are thousands of different ants, and another type might behave quite differently.

Based on my observations, ants don’t like coffee grounds, but they don’t create a major problem for them. They will go around them, ignore them or just move them out of the way. Since I monitor the rock garden closely, I am quite sure the ants had not been there for long, and I am guessing that in the case of the small plant, they had not yet made much investment into their home–so it was easier to move on than to fight me and the grounds.

Unless someone can provide better evidence, I must conclude that coffee grounds are not a good way to get rid of the type of ants I have in my garden.

Other Ways to Get Rid of Ants

Mint is reported to work to deter ants – find out if it works here:  How to Get Rid of Ants With Mint

Coffee Grounds in Garden

What can you do with coffee grounds? How can they be used in the garden? I covered some ideas in my last post which can be found here; Coffee Ground in Garden.

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Robert Pavlis

I have been gardening my whole life and have a science background. Besides writing and speaking about gardening, I own and operate a 6 acre private garden called Aspen Grove Gardens which now has over 3,000 perennials, grasses, shrubs and trees. Yes--I am a plantaholic!

33 thoughts on “How To Get Rid of Ants With Coffee Grounds”

  1. I tried with powdered cinnamon, cinnamon sticks, cinnamon essential oil. It did not repel the PHARAOH ants in my kitchen. Not sure who thought up of that one.
    More research needs to be done to see what these tiny jerks hate and how to quickly get rid of them. I squish them with a tissue drenched in vinegar and they are still alive. I use bait but as soon as they are gone, a few days later they are in another area of the kitchen. They are fast too.These pests are not like the regular black ants. I’d compare them to roaches.

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  2. Ants do most of their navigating by smell, it’s also how they recognise each other. Maybe the odour of the coffee is covering up their pheromones.

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  3. When I used live on a 2.5 acre property, every year when it started to get warm, the ants would come out looking for water and food for sustenance. They would come in the house and anywhere near it for tidbits and treats. What I would do was boil a gallon of water then add 2 cups of sugar. When this concoction cooled down I would pour it into the soil at the furthest and less used corner of the property. And then pour a cup of honey on top of the soil as a lure.
    This method worked year after year. They were so busy obtaining the sweet dirt particles and processing the fuel provided at the far end of the property…. that they didn’t bother trying to get what they needed from my house and walkways…
    There were multiple colonies and species of ants and this seemed to work for all of them. Although some years I would have to put the bait in 2 different locations because some species of ants did not want to go near other more dominant types of ants.
    In hypothesis it worked great every year for me because it kept them and the things that feed upon them away from my house.

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  4. Both native and Red Imported Fire Ants can sting. Red Imported Fire Ants are very aggressive and their sting can cause reactions ranging from irritation and nausea to even more severe reactions.Red Fire Ants are also known to attack animals that intrude on their nests.

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  5. Im in Panama on Vacation, and i though I woukd get rid of ants on the patio with coffee grains, but they seem to be carrying the grains to their collony. I wish i could send you a video.. Lol

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  6. Actual coffee. Saturate their hills with your old actual coffee.

    It will force the ones in the mound down into the tunnels. They will not rebuild the mound because it’s contaminated with the stink of coffee. Eventually, the colony will starve.

    It works. Have killed many colonies this way.

    When they are coming in the house – Borax mixed with something sweet. They carry the borax back to the colony, and eventually it is fed to the queen and the larve. No queen, no colony.

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      • I had problems with red ants a few summer ago, and read about coffee grains. I kept knocking the hill down and watched I guess a really huge queen build it back up late night. I got really tired of those ants. I boiled coffee, took a straw and put coffee grains down a hole. The next few days it was as if it just dried up. The went outside of my yard and I did the same thing. No eat hills for a few summers.

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  7. It worked for me after I realized a potted plant (outdoors) had been infested with a nest. I was growing edible plants so didn’t want to mess with pesticides. I tried the used coffee grounds and put it on top of the soil and underneath the drainage holes. Within a day all the ants had disappeared. It went from thousands to zero in a snap and I haven’t had any in there since.

    I started using them around and/or in my other containers and have seen less ants in my potted plants than before I started using coffee grounds.

    However, I’ve had lousy results outside of containers. It seems to do nothing in my yard or landscape as they just avoid it for a few days and then ignore it after that.

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  8. Going to try the coffee grounds but in FL I have found orange oil/ d-Limonene. It’s orange peel oil and it kills on contact. It dissolves there hard exoskeleton. I find it cheapest on Amazon. Make 3-4gal at 4oz per gal and make the same in sprayer. I stir up the nest. Wife sprays to keep them at bay while I flood the mound any ant the comes in contact dies… use enough water to reach to bottem of the nest to get the queen!!!

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  9. Ants can be a problem in the garden since they protect aphids from some predators.

    I have tiny fire ants that farm aphids on my vegetable garden, using the irrigation lines as highways. Many of them die on the tomato stems. Apparently the get stuck on the hairs of the stem. I suspect their small size makes them vulnerable to this.

    I prefer not to kill anything, so gardening is a bit of challenge for me.
    My approach is to create the right ecological conditions for the survival of my plants, allowing the balance of nature to keep pests in balance.

    Reply

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