How to Kill Ants with Borax [Easy DIY Guide]

Most people don’t notice that they have ants in the house until a large colony has formed. These pests can hibernate during winter and then make a grand appearance when the weather is warmer. By this time they have already established colonies and you are suddenly faced with a literal invasion.

Ants get into your house through doors, windows, gaps in the foundation, and through utility lines among other spaces. Getting rid of ants may seem like an impossible task but borax might just be that special weapon that you need to control your ant infestation once and for all.

Let’s learn how to kill ants with borax.

What is Borax?

Borax, also known as disodium tetraborate, sodium tetraborate or sodium borate, is a naturally occurring alkaline mineral often found in arid areas, specifically in saline lakes, playas, and hot springs.

Milliard Borax Powder - Pure Multipurpose Cleaning Agent, Laundry Detergent...
  • Made from anhydrous pure powdered sodium borate with no additives or preservatives.
  • Use as a cleansing booster with your laundry or dish detergent or DIY for Laundry Soap, Fabric Softener, Carpet...
  • Borax can be used for a variety of things from rust remover to refrigerator deodorizer.

Borax is a boron compound and appears naturally where seasonal lakes evaporate repeatedly. The mineral is mined commercially in Searles Lake, California and in the Southwestern United States. This mineral may also be extracted synthetically from boron compounds.

Borax is a low-toxicity compound if used properly and in the correct measure.

Borax vs. Boric Acid

The terms Borax and Boric acid are often used interchangeably and although both these substances are boron compounds, there are a few differences between the two minerals that are worthy of note.

Borax refers to the natural mineral that is collected from evaporated deposits or mined from the ground. When the borax is mixed with other natural minerals such as colemanite or boracites, the resulting compound is boric acid. Borax is, therefore, a salt of boric acid.

Structural formula of Boric Acid

Both borax and boric acid may be used interchangeably for killing ants. In fact, it is advisable that you substitute borax for boric acid if you notice that the ants are not attracted to the borax bait. Studies show that some ant species are more likely to reject borax baits than boric acid baits and vice-versa.

Note that boric acid, although generally safe when used in the right amount and when handled properly, is slightly more toxic than borax so exercise the appropriate caution when using this product.

Would you rather have a professional tackle your ant problem?
We’ll refer you to a qualified pest control professional that can provide a free quote – just fill out the form below and they’ll contact you!
Please just start with your area code and no hyphens.
By submitting this form, I am giving my express written consent to be contacted by email and/or telephone at the telephone number provided above in regards to pest control services.

How Borax Kills Ants

Borax has relatively low toxicity to humans and animals but the same cannot be said for ants. The mineral affects the digestive system of ants once ingested, and causes them to die eventually. Borax is a slow-acting agent which is why it is so effective for ant control.

The worker ants carry the poison back to the nest where it is ingested by other members of the colony including the queen. This method effectively eliminates the entire ant colony rather than only the ants that come into contact with the poison.

It is worth noting that the ants aren’t attracted to borax on its own. The compound has to be mixed with bait which is what attracts the ant in the first place. Think of it as preparing a delicious, poisoned feast for your unwanted guests.

If you’re mixing borax with a bait on your own at home, the best bait depends on the type of ant you have. Some ants prefer sugar in which case sugar-water is a great option. Other ants prefer proteins in which case peanut butter is your go-to (more on this later).

Ants that consume the bait may begin to die in as little as 24-48 hours. The amount of time it takes to eliminate the entire colony depends on a number of factors including the effectiveness of your bait, bait placement, and the size of the colony among other factors.

DIY Borax Mixes vs. Store-Bought Baits Containing Borax

DIY borax mixes are cheap and easy to make but may not be as effective at attracting ants as store-bought solutions. Companies that sell traps have lab-tested their bait for maximum ant attraction whereas when you DIY, it’s easy to use too much borax or too little bait which doesn’t lure the ants in optimally.

Simply put, the best ant baits aren’t those you make yourself!

Terro PCO Ant Bait Stations – 30 stations
Active Ingredient: Borax 5.4%

Terro-PCO is a liquid borate bait that instantly attracts and kills ants and their colonies. Terro-PCO is easy to use, has no unpleasant odors, may be used indoors and outdoors, and comes ready to use in pre-filled bait station

Why DoMyOwn? offers professional-grade insecticides to DIYers while ensuring proper storage of chemicals. Couple that with their impressive customer service and knowledgeable staff, it’s the #1 choice.

A more sure-fire way of getting rid of ants at home is to use store-bought ant traps such as the one above. Some of the reasons to choose store-bought baits over DIY borax mixes include:

Optimal Bait/Borax Ratio

Getting your borax mixture right is difficult and takes a lot of experimenting. To demonstrate this point, experts believe that the optimal concentration of liquid borate in a sugar-water solution is 0.5-1.0%. Additionally, the recommended amount of borate in ant bait targeting Argentine ants is 5.4%.  

Store-bought ant baits typically have the optimal bait and borax combination which takes out the headache of constantly refining and experimenting with your homemade baits.

Self-Contained Housing

Keeping your ant bait in open containers allows the ant easy access to the poisoned bait but that also means that your children and pets can also get to the substance. Borax may be low-toxicity to humans and pets but that doesn’t mean that it is 100% safe to use in the home.

Keep borax and borax baits away from children and pets. Store-bought baits typically come in self-contained housing that is pet and childproof while still allowing the tiny ants access to the bait.

The self-contained housing also means less mess and unsightly containers all around the house when using these baits.

Less Contact with Active Ingredient

Borax may be mildly toxic but it is still not a substance that you want to handle unnecessarily. Store-bought baits generally come in ready-to-use containers where you only need to open and place the bait without touching any toxic substance.   

Store-bought ant traps generally work better than homemade solutions

Side effects of acute borax exposure include skin rash, vomiting, mouth infection, nausea, and respiratory problems.

Using Borax Outdoors

Keep in mind that borax is also an herbicide so you want to be careful about using it outdoors. Rainwater can drain borax into the soil and plants and kill them.

There is also the risk of killing indigenous insects that are beneficial to your garden’s ecosystem when using borax baits indiscriminately. Store-bought outdoor baits are a much safer bet and usually have these considerations built into their use.

How to Make a Borax Ant Killer

If you want to mix your own borax ant killer, it’s relatively easy to do.

The good news is that all ant species have the same basic digestive system. That means that borax can be an effective ant killer regardless of the type of ant you have. The main challenge will be to entice the little pests to consume and share the borax poison.

Keep in mind that various ant species have different feeding habits and food preferences. A single species of ant also has different nutritional needs depending on the season and may change its food preference mid-way into you setting up the ant traps. It is for these reasons that you may have to experiment with various kinds of home-made borax ant baits until you find one that the ants will actually take.

Borax and Peanut Butter Bait [for protein feeding ants]

For this ant bait, mix one teaspoon of peanut butter and two teaspoons of borax. Blend the ingredients thoroughly and place in bottle caps or other open containers. You can also add 2 tablespoons of honey to the mixture if the ants do not respond to the initial bait. Protein ants may need sugar in their diet during certain seasons.

Protein and grease-feeding ants can’t resist peanut butter!

Place the baits along ant trails that you have seen for the best effect. This is a great recipe for protein-feeding ants such as odorous house ants, Argentine ants, pharaoh ants, southern fire ant, thief ant, red imported fire ant, and pavement ants among others.

Borax and Sugar Bait [for sugar-feeding ants]

Mix 1 cup of water, 2 cups of sugar, and 2 tablespoons of borax in a saucepan. Bring the mixture to a boil while stirring thoroughly to mix the ingredients.

Allow the mixture to cool. The bait will thicken into a paste when it cools. Put the bait in your open containers or pieces of cardboard/foil and place the baits along ant trails.

This recipe is good for sugar-feeding ants such as big-headed ants, black ants, acrobat ants, ghost ants, crazy ants, white-footed ants, little black ants, cornfield ants, carpenter ants, odorous house ants, and pavement ants among others.   

Borax and Jam Bait [for sugar feeding ants]

This ant bait is a good alternative for the sugar recipe described above. To make the ant bait, mix a small amount of jam with 2 tablespoons of borax and combine thoroughly. Put the mixture on a piece of cardboard or open container and wait.

This recipe works well for sugar-feeding ants and can be used together with the sugar and borax bait to give the ants some variety in their diet.

How Borax Compares With Other Ant Traps

The main thing to consider when comparing the various ant traps is the main active ingredient in each of them.


Hydramethylnon is typically used in gel baits and targets a wide range of ants including fire ants, carpenter ants, and Argentine ants. This ingredient is not extensively absorbed through the skin and has low toxicity to humans. Hydramethylnon interferes with reproduction at moderate doses and is toxic to a developing fetus.


Fipronil has a wide range of uses in various types of ant baits including liquid, gel, and granular baits. Fipronil is not absorbed substantially through the skin but is considered moderately acutely toxic to humans when ingested. Fipronil is toxic to the nervous system.


Avermectin is typically used in granular baits and is effective for controlling carpenter ants, Argentine ants, and fire ants. Avermectin is used in small doses in ants baits (less than 0.01%) and has low acute toxicity to humans. This ingredient is not absorbed through the skin in great amounts but can be toxic to the nervous system and developing fetuses at very low doses.


Fenoxycarb is used in baits specifically targeting fire ants and generally comes in granular form. It is not well absorbed through the skin and has low acute toxicity to humans. This compound is toxic to the liver with long-term exposure.

Cyfluthrin and Permethrin

Keep these two ingredients in mind when you are shopping for ant traps. Cyfluthrin and Permethrin are sometimes used in ant baits but these active ingredients work on contact.

The potent chemicals kill ants almost instantly meaning that the workers do not get a chance to carry the bait to the rest of the colony. Cyfluthrin and Permethrin-based ant baits can be very effective for killing visible ants but are a poor long-term solution since the queens continue to reproduce and add new workers to the colony.  

So why choose borax?

Generally speaking, ant baits have low-toxicity to humans since the active ingredients are used in small amounts. Of all the active ingredients typically used in these products, borax and borate-based baits are the least toxic.

Borax is not absorbed through the skin and is only toxic when misused or ingested in small amounts daily over a period of months. Borax is a ‘natural’ ant killer and a good alternative for people who are not keen on using potent chemical formulations in their homes.

This mineral is also as effective for exterminating ants as any of the other active ingredients available on the market.

Keep in mind that although mildly toxic, borax should still be handled with care and kept away from children and pets.

Final Thoughts on Using Borax for Ant Control

You can certainly use a borax mixture to get rid of ants and many homeowners have had great success following this method. If you prefer to make your own bait, lay out different kinds of baits (without borax) and monitor which ones the ants are attracted to.

Laying the bait before mixing in the borax also allows the ants to get used to the food source and alert other workers to the new scavenging location.

Store-bought baits tend to work better. You may need to try out a few options before you find one that works. Even then, switch the type/brand of bait periodically since ants can develop tolerance to the bait with long-term exposure.

Remember to keep the ant baits away from children and pets including homemade and store-bought baits. An ant infestation can be frustrating to exterminate but borax is one of the best and safest products to use indoors to control ants.

Check out our recommended borax for killing ants –

TERRO T300B Liquid Ant Killer, 12 Bait Stations
  • Attracts & Kills – Kills common household ants including acrobat, crazy, ghost, little black, odorous house, pavement,...
  • Kills the Ants You See & the Ones You Don't – As worker ants discover the bait, they share it with the rest of the...
  • Works Fast – You should see a significant decrease in the number of ants visiting the bait stations within just a few...

Other Uses for Borax at Home

Borax has plenty of uses other than for pest control. A few situations where a box of borax in the home may come in handy include:

Cleaning your Carpets

Mix a ½ cup of borax per gallon of water and pour the solution into your carpet cleaner’s reservoir tank for extra cleaning power!

Killing Weeds

Borax is a great natural herbicide for those pesky weeds that like to grow in the cracks of your walkways. Sprinkle a little borax on top of the weeds to kill them.

Deodorizing your Refrigerator

Borax is perfect for removing grime and spills inside the refrigerator. Mix 1 tablespoon borax and 1 quart of warm water to make your home-made cleaning solution. Pour the mixture into a spray bottle and spray directly on the stains and wipe with a clean cloth.

Borax also has a deodorizing effect and will get rid of those stale odors.

Removing Rust

A borax mixture is good for removing rust

To create your rust remover, mix 1 tablespoon of fresh lemon juice and 2 tablespoons of borax. Add a little amount of water to the mixture to create a paste. Use a sponge to apply the paste to the rusted item and scrub to remove the rust. Rinse the item thoroughly after removing the rust.

Uncloging Drains

Mix ½ a cup of borax with 2 cups of boiling water. Pour the mixture into your drain and wait 15 minutes before running warm water through the drain for 1-2 minutes. The borax should help to unclog the drain. Repeat the procedure as necessary for stubborn clogs.

Removing Sink Stains

A borax paste may be what you need to get rid of those stubborn sink stains. Mix in 1 cup of borax with a ¼ cup of fresh lemon juice to create the paste. Rub the paste directly on the stains using a cloth or sponge and rinse with warm water.

All-Purpose Cleaner

A home-made borax all-purpose cleaner is effective for getting rid of stubborn stains including pencil and crayon markings on walls. To make the cleaner, simply mix 2 tablespoons of borax with 2 cups of hot water. Pour the mixture into a spray bottle and shake vigorously. Allow the solution to cool and use it to get rid of stubborn stains. This all-purpose cleaner also works well for degreasing countertops and stoves.

Washing Detergent

Pour ½ a cup of borax in your laundry to remove stubborn stains in clothes. The borax also acts as a natural deodorizer, leaving your clothes smelling fresh without any artificial scent.

Borax is also great for pre-treating stained clothes. Simply mix a ½ cup of borax in warm water and soak your stained clothes for at least half an hour before washing.  

Borax in Commercial Applications

Borax is used for many commercial applications including:

Household Products

20 Mule Team brand is almost synonymous with borax

Borax features in many household cleaning and laundry products including laundry boosters, hand soaps, and tooth bleaching formulas.

Water Softener

Borax is often used for water-softening including removing both temporary and permanent types of hardness.


Flux is used in welding to protect the surface of the weld from foreign gasses by preventing oxidation from taking place on the said surface.

Borax is often used in various welding applications. In steel and iron welding, borax is mixed with ammonium chloride and used as a flux. Borax may also be mixed with water and used as a flux when soldering jewelry materials such as silver and gold.

Food Additive

Borax has been used as a food preservative since ancient times. Some countries such as the United States, Thailand, and China have banned borax as a food additive. Borax may also be used to add a rubbery and/or firm texture to foods such as rice noodles and wheat.

Borax is also used as an ingredient in enamel glazes, as a fire retardant, as a component in ceramics, glass and pottery, and for making indelible ink among other commercial applications.

Would you rather have a professional tackle your ant problem?
We’ll refer you to a qualified pest control professional that can provide a free quote – just fill out the form below and they’ll contact you!
Please just start with your area code and no hyphens.
By submitting this form, I am giving my express written consent to be contacted by email and/or telephone at the telephone number provided above in regards to pest control services.

Want Help from a Pro?

Get a quick, easy, FREE, no obligation quote from a trusted exterminator.

Written by Ben Cannon


Leave a Reply
  1. I have some very tiny almost microscopic ants tan almost reddish color that I suspect are thief ants because they like protein. I mixed up 5 parts combo of peanut butter and powdered sugar mixture to 1 part 20 mule team borax. They have been eating it non stop for four days. I don’t see any dead ants, just tons of very hungry ants. I also had some winged ants swarm and killed all of those I saw. A couple of those flew to the bait and died. I don’t know if it was males just dying. One was a female because I think her wings had fallen off. But they are still coming in droves into my house to tie bait and I’m terrified that I’m just feeding them and not getting rid of them. We tried to find where they are coming in and can’t because they are in my wall behind the kitchen sink and the house is over 100 years old with a million cracks. I’m afraid I’m attracting more ants in from huge colonies. I’m afraid to have exterminator come in be praise of coronavirus. Is my bait strong enough? Is it normal to attract a tone more ants for days on end before I see a change? They killed out a previous colony of black ants and I’ve noticed them in and off for two years. They couldn’t have multiple colonies in the yard because my husband has a recycle metal pile and my have brought them from collected beer cans. Tell me if this bait mixture is going to work or if I’m making it worse. They would eat terro baits and Maggie farm baits for a short while and quit after it killed a bunch of them on the counter. They don’t prefer those. But it must have been too strong because it didn’t kill the colony. It is July and swarm time but I didn’t see any winged ants flying yesterday whereas before there was three days of flying ants and may have been a total of around 15 of them. What ratio of 20 mule team will kill the colony by taking it to the nest? I’m afraid. Help!

Leave a Reply

Your email address will not be published.