How to Use Borax to Get Rid of Ants, Cockroaches, and More

You may be familiar with borax as a laundry booster, or possibly as a carpet deodorizer, stain remover, or mold and mildew killer. Borax has been a popular household cleaning staple for over a hundred years. It cleans soap scum and grime, sinks and toilets, outdoor furniture, and more. But its most surprising application might be pest control.

If you've ever had an ant infestation and asked for advice from neighbors, borax has probably come up. It's lauded as one of the best natural methods to rid your home of certain pests. But there is a lot to know about borax before you start lining your property with this white powder. Learning how to use it properly as a pest control agent is critical, as it could cause harm if applied incorrectly.

To learn how to use borax correctly, we consulted pest control experts. Ahead, we're sharing all you need to know about borax and how to use it safely so that you are prepared when ants (and other insects) come marching in.

What Is Borax?

Borax is a naturally formed mineral compound known as sodium borate (boron, sodium, oxygen, and water). It is mined from evaporite deposits formed by the evaporation of mineral-rich water and is later processed into a white, water-soluble powder, says pest control expert Tony King.

Why Borax Is an Effective Pesticide

Borax is very effective against many pests because of its toxicity, but it may not work in the way one would expect. "It doesn't kill pests right away as chemical sprays do," says Allan Bossel, operations expert at Bed Bug Exterminator. "You can't just spray a borax solution on ants and cockroaches and expect them to drop dead on the spot."

Borax is a slow-acting poison that works by gradually damaging the digestive system of insects, which prevents them from absorbing nutrients, thereby reducing their overall strength. It also dehydrates them by destroying their exoskeletons, further weakening them and eventually resulting in death.

The slow-acting nature of borax is advantageous, as it allows exposed worker insects like ants and roaches to bring the poison back to their colonies and spread it there, eventually killing the whole colony. "This is why most ant baits are still borax-based," says Bossel.

Additionally, borax's fine powder consistency easily sticks to the legs and bodies of cockroaches, and since roaches are heavy groomers, the chance some of the poison gets ingested is high, says Carpenter.

What Borax Will and Won’t Kill

Borax is an effective insect pest control solution, but it won't work on everything. "A combination of the natural toxicity of borax and the fact that borax has been transferred throughout a colony makes it an excellent choice for controlling small household pests that consume baits, including ants, roaches, silverfish, carpet beetles, and various types of grain or pantry pests," King says.

However, borax will not work on pests that aren't interested in eating it, such as termites, bed bugs, mosquitoes, flying insects above ground level, or any number of other outdoor pests, such as slugs and snails.

Once you have identified the insects in question, make sure that a borax-bait-based based control method will be successful for this specific pest. Then carefully consider the application and placement of your bait before proceeding.

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How to Use Borax in the Garden

Applying borax in your garden should be done with great care, as it can be toxic to humans, pets, and birds if ingested or inhaled in large quantities. For this reason, Carpenter recommends using bait stations that contain borax, rather than sprinkling borax directly into the garden. Not only does borax kill ants, but it also damages plants, builds up in the soil, washes into places you don't intend, and is more easily encountered by kids and animals, she says.

Ready-made outdoor bait stations are safely designed so that ants can get inside and take the bait, but pets, birds, and kids can't easily reach them. Carpenter recommends weighing the bait stations down with something, as they are lightweight and can spill when exposed to wind.

Place the bait stations along visible ant trails, near the edges of garden beds, along borders, fence lines, patios, or paths where ants travel, keeping roughly 5 to 10 feet of distance between them. "For an average garden, five to six stations are usually enough if you place them where ants travel," Carpenter says.

Even when applying bait solution to highly concentrated areas of pest activity, such as ant trails or around nest entrances, King recommends being careful to avoid any direct contact with edible plants or plant roots. "I will continue to watch the area over multiple days and only repeat treatment if necessary to ensure I am not harming beneficial organisms that live in the soil or affecting plant growth or health," he says.

How to Use Borax Inside

For indoor pest problems, King says you can make a liquid borax solution by dissolving a small amount of borax in water and adding a sweet attractant such as sugar, syrup, or a starchy food source that attracts pests.

Apply the liquid bait in strategic areas such as behind kitchen appliances, under sinks, or along baseboard lines where pest activity occurs. "Use small amounts and safely secure placement to minimize risk of exposure to children or pests," he cautions. Continue observing pest activity and remove or replace bait as required, avoiding excessive use, as a small amount is usually adequate to eradicate a pest population over time, says King.

Carpenter says you can also use bait stations indoors. "Start with two to three bait stations and put them exactly where you see ants, keeping the distance up to 10 feet," she says. For cockroaches, Carpenter prefers a very light dusting of borax over bait stations, but only in hidden areas like under appliances that pets, kids, and food cannot access.

How to Use Borax Powder Safely

It's essential to exercise caution when using borax for pest control. "Borax is not something that kills humans immediately, but for kids and pets, which are smaller, an accidental ingestion or inhaling can end in vomiting, diarrhea, stomach pain, lethargy, and tremors,” warns Carpenter. "Furthermore, improperly applying borax outdoors can lead to long-term environmental problems, since excess boron can accumulate in the soil, resulting in negative impacts on plant development," says King.

For these reasons, safety precautions are paramount when using borax. Follow these professional safety tips to get the most out of your borax without causing any harm to yourself or others.

• Store borax safely: Store borax in its original packaging or a clearly marked, sealed container at a safe height away from food, young children, and pets, says King. Keep it away from water sources and drains so it does not contaminate the surrounding environment.
• Wear gloves: Wear protective gloves (disposable or washable) when handling borax to protect yourself from potential skin irritation and unintentional transfer, says King.
• Be cautious when applying: Don't shake the borax too aggressively to avoid generating dust, says King. Wear a mask to prevent accidental inhalation.
• Position your bait away from plants: Borax can build up in soil and damage plants, so it's better to place bait stations at least 3 to 5 feet away from your vegetable beds, says Carpenter.
• Use labels: Label all areas treated with borax so others in your home know they exist, says King.
• Wash your hands after handling: Immediately wash your hands with soap and water after handling borax, whether or not you have been wearing gloves, says King.
• Get rid of the bait when done: Once you have eradicated the pest issue, dispose of any remaining bait or bait stations to avoid accidental exposure, says King.