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Borax Ant Killer: 3 Natural Methods to Kill Ants (Fast) in 20 Minutes

Borax and sugar to kill ants

Ants have invaded your home. Like thieves in the night, they’re marching through your kitchen, clamoring to get every last crumb they can find on you counters. How do you get rid of them without using toxic sprays or hiring an exterminator?


Yes, that same stuff your grandma used to wash laundry can also get rid of ants. Read on to learn more about why borax is an ant killer and how to use it to kill those pesky ants.

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What is Borax?

Most people are familiar with the 20 Mule Team brand of borax, and that’s the type you’ll find in most stores. This white powdery substance is made of sodium borate or sodium tetraborate.

Many people mistake borax for boric acid, but the two are not the same by any means.

FYI: Boric acid is hydrogen borate.

Borax is actually a natural mineral, and it’s found all over the world. Its crystals are either white or clear, depending on how pure the mineral is and the conditions it was formed in.

Known for its cleaning power, you’ll often find borax listed as an ingredient in popular DIY cleaning recipes. Borax is also used as:

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  • An insect killer
  • An herbicide
  • A fungicide
  • A laundry booster
  • A desiccant

That first use (insect killer) is what we’re most interested in.

Can you really use borax to kill ants? Does it really work?

Does Borax Kill Ants?Open hand raised, with Stop Ants sign painted.

Yes – and it’s one of the most effective methods, too. Borax is actually the active ingredient in most commercial ant baits, so you know it works well. And it does more than just kill the ants that come in contact with it – it has the power to kill the entire colony.

How Borax Kills Ants

How can a white powdery substance kill an ant? Through the digestive system.

Borax isn’t a quick killer by any means, but that’s what makes it so effective. When the ant eats the borax, it interferes with its digestive system to kill them gradually. Meanwhile, the affected ant has enough time to bring the bait back to the colony, where he’ll share his “spoils” with the others and kill them, too.

Ants won’t be attracted to just the borax though. You’ll need to make borax ant bait to lure them in and entice them to take the bait back to the nest.

Will Borax Kill Fire Ants?

Yes, thankfully. Borax will have the same effect on fire ants as it will on carpenter, sugar or most other types of ants. Because their digestive systems work in the same way, borax will effectively kill just about all species of ants.

There’s one important thing to note here – if you do have fire ants, try to only kill the fire ants and not the regular ants. Chances are, you’re dealing with fire ants in the yard (at least we hope these pesky and painful critters aren’t in your home), and there’s likely to be a colony of sugar or carpenter ants nearby.

If you kill all the ants in your yard, you leave room for more fire ants to come in and expand their presence even further. Fire ants are an invasive species, and indigenous ants are competition – they limit their options for shelter and food. So, do your best to just target the fire ants if you can.

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Will Borax Kill Carpenter Ants?

Borax can kill carpenter ants, but not quite as effectively. Carpenter ants in general are a little more difficult to get rid of. They won’t actually take the bait back to the nest, so you’ll need to kill the ants at the source –their nest.

Diatomaceous earth is a better option for killing carpenter ants. It actually shreds their insides, killing them pretty quickly.

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How to Kill Ants with Borax

Using borax for ants is a natural, effective way to get rid of an infestation, and there are several ways to use this powdery substance to get rid of those critters invading your home or yard.

But before you make your ant poison with borax, you first need to figure out where the ants are coming from. Otherwise, they won’t find your sweet poison, and you won’t know why your ant invasion is only getting worse.

Follow the Trail – The Ant TrailThe picture shows the trail of ants on orange background.

Where are the ants coming from? One easy way to figure out where they’re coming from (or how they’re getting into your home) is to follow any trails of ants you see.

When ants locate a food source, they leave a pheromone trail behind. That pheromone trail is sort of like a GPS that lets other ants know where the grub is. The other ants follow the path and keep the pheromone trail going.

These trails are also great places to put your bait, but you’ll also want to try and place some near entryways to catch them before they even get inside.

Borax Ant Killer Recipe

To make your own DIY ant trap, all you need is a little water, borax and sugar.

  • 1/2 cup sugar
  • 2 tablespoons borax
  • 1 1/2 cups water

Mix warm water with the sugar and borax until the powder dissolves completely. Pour the mixture in plastic jar caps or bowls, and place the bait where ants are known to frequent. Use the results from your earlier investigative work to place the bait in strategic locations.

The sugar is what will attract the ants, and the borax is what will kill them. The water just makes it easier for the ants to transport the goods back to their nest.

Does Borax Kill Ants Outside?

Yes. Borax will work the same way to kill ants whether it’s outside or inside. While using it outdoors can be a little trickier, it can help stop an invasion before it even makes it into your home.

Here’s an effective way to use borax outside to kill ants in your yard:

  • Mix equal parts granulated sugar (a.k.a. white sugar) and borax

That’s it! Just sprinkle the mixture in your yard where ants are hanging around. The mixture will work in the same way to kill the colony. It may kill other insects, too, so keep this in mind.

And while borax is not quite as toxic as boric acid, you still want to be careful if you have pets or kids that play in the yard. You certainly don’t want your little one or your furry friend eating this mixture, so do be cautious when using this mixture outdoors.

We recommend sprinkling a little bit of the mixture at a time. This will allow you to keep tabs on whether the ants are actually taking the bait. Just reapply the bait every few days for best results.

Tip: If it rains, you’ll need to reapply the mixture. The rain will dissolve the borax and the sugar. If you know a rainstorm is coming, you may want to hold off a day or two before sprinkling the mixture outdoors.

What is Borax Substitute?

If you prefer not to use borax or don’t have any in your home and need an emergency solution, some people have had success mixing equal parts baking powder or baking soda and sugar.

How to Get Rid of Ants Naturally – 3 Other Methods

If you’d rather avoid using borax or if borax didn’t work for you, there are other natural ways to get rid of ants. These three methods are the most effective:

1. CinnamonCinnamon sticks and ground cinnamon in bowl isolated on white background.

Ants hate cinnamon. One effective way to keep ants out of your home is to spray cinnamon essential oils on any doors or openings in your home. If you’d rather not spray the mixture, you can dip a Q-tip in the oil, and apply it to entryways.

Some people use ground cinnamon, although the powder can be a little messy.

As an added bonus, your house will smell amazing.

2. Keep Your Home Tidy

While this method won’t kill ants, it will deter them. Ants have three basic needs: food, water and shelter. Take away the food, and you’ve taken a huge step towards deterring these critters from infiltrating your home.

Keep your home clean and free of any food sources that may attract ants. Keep food sealed in airtight containers, wash dirty dishes right away, and sweep floors daily.

Removing all of the possible food sources from your home will help keep ants away.

3. Boiling Water and Dish Soap

A mixture of boiling water and dish soap can also kill ants. But this method is better suited for those few stragglers that may get in, but haven’t set up a nest.

Once the ants come in contact with the dish soap/water, they die in minutes.

And if you want to get rid of the ants’ pheromone trails, spray a mixture of vinegar and water along the ant trails. The vinegar neutralizes the ants’ chemicals, so colony mates won’t find their way back into your home.

Use the vinegar trick along with the borax bait to kill the colony and prevent any survivors from coming back into your home. Just make sure that you wait until after the borax has worked its magic to destroy the chemical trail. Otherwise, the ants won’t know how to get to the bait.