Does Baking Soda Kill Ants? What the Science Says and How to Use It

TL;DR

• Yes, partly. Baking soda kills only the ants that eat enough of it, and it rarely wipes out a whole colony.
• In lab studies, about 50% of Argentine ant workers died after 6 days on sugar water with 5% baking soda. It has no published tests in real homes.
• Ants have to eat it, so mix equal parts baking soda and powdered sugar and set it out where ants are already feeding.
• Give the bait at least two weeks before deciding whether it works.
• Registered slow-acting baits work better for most indoor ant problems. Ants still coming back after a few weeks of baiting? Call a pest control professional.
• Need help? Get a quote from a recommended local exterminator through Pest Agent's referral form.

Baking soda does kill ants, but only the workers that swallow enough of it, and the queen back in the nest is rarely among them. That gap matters when you are standing in the kitchen deciding between a box from the pantry and a trip to the hardware store for a proper bait.

The pantry option has obvious appeal: it costs almost nothing and is low in toxicity. It is also not a registered ant product, and every result behind it comes from university lab tests, not from real homes. How much of a trail it actually wipes out depends on numbers that most recipe posts leave out.

Does Baking Soda Kill Ants?

Baking soda kills some ants, but only the ones that eat enough of it, and it rarely wipes out a whole colony. It is a low-cost, low-toxicity home remedy with modest results in the lab and no published tests in real homes. If you want to try it, go in with realistic expectations and a backup plan.

What Is Baking Soda?

Baking soda is sodium bicarbonate, the same white powder you use for baking and cleaning. It is not a registered pesticide in Canada: a box of baking soda has no Pest Control Products (PCP) number and no label directions for ants. That means nobody has tested it for ant control the way Health Canada requires for real ant baits, so results vary a lot from one home to another.

What Did Lab Studies Find?

Baking soda killed ants in university lab studies published in 2004, but not all of them. Entomologists, including a team at the University of Georgia, tested sodium bicarbonate on Argentine ants and red imported fire ants:

• About 50% of Argentine ant workers died after 6 days of feeding on sugar water with 5% baking soda.
• Only 42% of fire ant workers died after feeding on sugar water with 7.5% baking soda.
• Adding more baking soda to the sugar water did not kill more ants.
• Ants kept on surfaces heavily coated with baking soda died at higher rates, up to 89.5% of Argentine ants by day 6, a level of exposure you cannot reproduce with a small bait cap at home.

We could not find any published study that tested baking soda against ants inside real homes. So the honest answer is: it can work on some workers, under controlled conditions, over several days.

Does Baking Soda Kill the Whole Colony?

Baking soda rarely kills the whole colony. Only foraging workers eat the bait, and many may die before they carry it back and share it. The queen stays deep in the nest and keeps laying eggs, so new workers replace the ones you lost. If the trail shrinks for a few days and then comes back, that is usually why. For an overview of the species and methods that do reach the nest, start with our ant guides.

How Does Baking Soda Kill Ants?

Baking soda most likely kills ants by raising the pH inside their bodies, which disrupts the enzymes they need to survive. It works slowly, over days, and only after the ant swallows it.

The pH Effect

The pH effect is the explanation backed by research. In the University of Georgia study, fire ant workers that had not touched baking soda had a whole-body pH of 6.97, while workers exposed to it measured 7.90. The researchers concluded that this rise in internal pH, which upsets the ant's enzymes, was the most likely cause of death. A comparison with table salt in a related study supports this: the same amount of sodium as salt killed about 15% of fire ants, close to untreated ants, while baking soda killed about 46% after 6 days.

Does Baking Soda Make Ants Explode?

Baking soda does not make ants explode. The popular story says baking soda reacts with acid inside the ant, releases carbon dioxide gas and bursts the insect. There is no strong research behind that claim. A similar carbon dioxide myth says club soda suffocates fire ant colonies: when Texas AgriLife Extension entomologist Wizzie Brown tested it on mounds in 2009, it produced "lots of impressive bubbling action" and no control.

Why Ants Have to Eat It

Ants have to eat baking soda for it to do anything, and that is harder than it sounds. Adult worker ants mainly drink liquids: solid particles get caught in a small pouch behind the mouth and are spat out as a pellet. A dry pile of powder is therefore a weak way to deliver it. Sugar is what gets ants to take the bait in the first place, which is why every baking soda recipe pairs it with something sweet.

How Do You Make a Baking Soda and Sugar Ant Killer?

A baking soda and sugar ant killer is equal parts baking soda and powdered sugar, set out where ants are already feeding. It is the most common home version, reported by several pest control companies, though nobody has tested this exact mix in a lab.

Recipe

1. Mix about 1 tablespoon of baking soda with 1 tablespoon of powdered sugar in a small bowl.
2. Stir until the two powders look the same and you cannot see white baking soda streaks.
3. Spoon the mix into a shallow bottle cap, jar lid or small dish.
4. Make several of these bait caps if you see ants in more than one spot.
5. Store any leftover mix in a sealed, labelled jar, away from food and out of reach of children.

Why Use Powdered Sugar?

Powdered sugar works better than granulated sugar because it blends evenly with the fine baking soda. With regular sugar, ants can pick out the sugar crystals and leave the baking soda behind.

Liquid Version

A liquid version may suit ants better, since workers drink liquids and the lab studies used sugar water. A common version stirs together 1 tablespoon each of sugar, water and baking soda. Pour a little into a shallow lid on the trail and replace it when it dries out or gets dirty. Keep in mind that adding more baking soda did not improve results in the lab.

Child and Pet Safety

Baking soda is low in toxicity, but it is not risk-free. Large amounts can be harmful to pets, and vomiting is usually the first sign. Put bait caps where children and pets cannot reach them, such as behind appliances or inside a cabinet the ants use, and call your veterinarian or an animal poison line if your pet eats a large amount. If you have pets, see our guide to pet-safe ant killers.

How Do You Use a Baking Soda Ant Killer?

A baking soda ant killer works only where ants are already walking, kept dry, and left alone for at least a week or two. The same rules Health Canada gives for real ant baits apply to the homemade kind.

Bait Placement

Bait placement makes or breaks a baking soda ant killer. Put the caps right on or beside active ant trails: along baseboards, cabinet edges, the back of the counter, under the sink or at the mouth of a wall crack where ants come in. Health Canada advises using plenty of bait stations rather than one, so place a cap at each trail you find. Wipe up crumbs and store food in sealed containers, as Health Canada recommends, so the bait becomes the easiest food around.

Do Not Spray While Baiting

Spraying while baiting stops any bait from working. Health Canada warns against using chemical sprays on the same ants you are baiting, because the ants die or scatter before they feed. Leave the trail alone too: wiping it with vinegar or cleaner erases the scent the ants follow to the bait.

How Long It Takes

Baking soda bait takes at least several days. UC IPM notes that even proper ant baits can take 5 to 10 days to show fewer ants, and Health Canada recommends keeping baits out for at least two weeks. Check the caps every few days and replace the mix if it gets wet or clumps, because damp powder stops attracting ants.

Signs It Is Not Working

Signs that baking soda is not working include ants walking around the bait without eating it, a trail that is just as busy after two weeks, and new trails in other rooms. Ant species also matter. Carpenter ants prefer protein and fat, so a sugar bait is unlikely to tempt them, and they can damage wood, so they need a different plan: see how to get rid of carpenter ants.

What Works Better Than Baking Soda for Ants?

Registered slow-acting baits work better than baking soda for most indoor ant problems in Canada. Health Canada notes that bait systems work well because ants carry the food back to the colony, which is exactly where baking soda falls short.

Borax Baits

Borax baits are the natural next step if baking soda fails. Borax and boric acid act slowly enough for workers to share the bait with the queen and larvae, and Health Canada says boric acid baits are generally low in toxicity to other animals. Borax can be toxic to children and pets, though, so keep it well out of their reach. Our guides on using borax to kill ants and boric acid ant killers explain how to choose and place a registered bait.

Commercial Ant Bait Stations

Commercial ant bait stations give you a measured, enclosed dose that has been tested on ants. Before you buy, check that the label lists the kind of ant you have and shows a PCP number, which means Health Canada has approved the product. Health Canada also suggests using two different baits at once for better results. For tested options, see our picks for the best ant killer.

Diatomaceous Earth

Diatomaceous earth is a dry powder you put in cracks and crevices where ants travel. Health Canada describes it as non-toxic to humans and pets, but you should avoid breathing in the dust. It works only on ants that walk through it and loses its effect when wet. Learn more in our guide to diatomaceous earth for ants.

Vinegar

Vinegar repels ants and erases their scent trails, but it does not kill the colony, so it is more of a short-term fix. Do not use it on a trail you are baiting. Find out more in does vinegar kill ants, and compare other pantry options in our roundup of homemade ant killers.

When to Call a Pest Control Professional

Calling a pest control professional makes sense when ants keep coming back after a few weeks of baiting, when you find ants in several rooms, or when you suspect carpenter ants, since they can damage the wood in your home. A licensed pest control professional can identify the species and find the nest. You can get a quote from a recommended local exterminator through Pest Agent's referral form.