Baking soda mixed with sugar can kill some ants, but it’s far less effective than most DIY websites suggest. Lab testing shows roughly 50% of worker ants die after six days of exposure to a baking soda and sugar bait, and higher concentrations don’t improve results much. It won’t eliminate a colony, and it doesn’t work equally well on all ant species.
How Baking Soda Kills Ants
Ants have formic acid in their digestive systems. When they eat baking soda, it reacts with that acid and produces carbon dioxide gas. The gas builds pressure inside the ant’s body, which can crack its exoskeleton and cause it to dry out. This isn’t instant. The ant has to consume enough of the baking soda mixture for the reaction to cause fatal damage.
Research on fire ants found that baking soda exposure raised their body pH from 6.97 to 7.90, a shift large enough to increase death rates. But there’s a gap between lab conditions and your kitchen counter. In a lab, researchers can control exactly how much baking soda ants encounter. In your home, ants may eat too little, avoid the bait entirely, or simply walk around it.
What the Numbers Actually Show
When researchers tested a bait made of 5% baking soda in a 10% sugar water solution on Argentine ants, it killed about 50% of workers over six days. Increasing the baking soda concentration didn’t improve the kill rate, which suggests ants either stop eating the bait when they detect something is off or their bodies can only absorb so much before they stop feeding. There appears to be a ceiling on how effective this method can be.
Surface treatments (sprinkling baking soda directly on ant trails) required about 4 milligrams per square centimeter to kill half the ants over six days. Higher amounts pushed kill rates to 89% or even 99%, but that level of direct contact is hard to replicate outside a controlled setting. You’d need ants to walk through a thick, undisturbed layer of powder repeatedly, which rarely happens in a real home.
Why It Won’t Eliminate a Colony
Even if baking soda kills the worker ants you can see, the queen stays safely inside the nest. As long as she’s alive, she keeps producing new workers. A colony can have thousands or even hundreds of thousands of ants, and the visible trail in your kitchen represents a tiny fraction of the total population. Baking soda bait doesn’t spread through a colony the way professional-grade products do. Workers that eat it tend to die before making it back to the nest, so the poison never reaches the queen or the brood.
This is the core limitation. Any ant control method that only kills foragers without reaching the nest is, at best, a temporary fix. You’ll reduce the visible ants for a few days, but the colony will send out new workers to replace them.
Some Ant Species Ignore It Entirely
The sugar in the mixture is the lure. It’s what attracts ants to eat the baking soda in the first place. That means this trick only works on species that actively seek out sugary food.
Odorous house ants (the small dark ones that smell like coconut when crushed) are sugar feeders and respond best to this type of bait. But they form multiple satellite colonies spread across different locations, so even killing workers from one trail barely dents the overall population.
Carpenter ants prefer protein and fat over sugar. They’re unlikely to eat a sugar-based bait at all, making the baking soda approach essentially useless against them. If you’re dealing with carpenter ants, addressing moisture problems and structural wood damage matters far more than any bait.
Fire ants need higher concentrations of baking soda and longer exposure times to show any effect. Their colonies are massive, often containing 100,000 or more workers, and their aggressive foraging behavior makes DIY baits impractical.
How Borax Compares
Borax (sold as a laundry booster) works on a fundamentally different principle that makes it more effective for colony elimination. Mixed with sugar and water, borax acts slowly enough that worker ants carry it back to the nest and feed it to other ants, including the queen and larvae. This is the key advantage: borax kills at the colony level, not just at the trail level.
A simple borax bait (borax mixed with sugar and warm water, placed near ant trails) typically produces noticeable results within a day and can clear visible ant activity within a few days. The delayed toxicity is a feature, not a bug. If a poison kills too fast, the worker dies before sharing the food. Borax hits the sweet spot where ants survive long enough to distribute it throughout the nest.
Some people report that baking soda and borax baits produce similar results, but the mechanism matters. Baking soda kills individual ants through a chemical reaction in the gut. Borax poisons the colony through food sharing. For long-term control, reaching the queen is what counts.
Making the Most of a Baking Soda Bait
If you want to try it anyway, mix equal parts baking soda and powdered sugar. Powdered sugar works better than granulated because ants can’t separate the two powders as easily. Place small amounts in shallow lids or on pieces of cardboard directly along active ant trails, close to where they enter your home.
Keep the bait dry. Moisture causes baking soda to clump and can make it less appealing. Replace it every two to three days. Expect to see some dead ants within 24 to 48 hours, but don’t expect the trail to stop entirely. If you’re still seeing heavy ant traffic after a week, the method isn’t working for your situation.
One common issue: some ants detect the baking soda and avoid the bait altogether. If ants walk up to your mixture and turn away, they’ve likely identified it as unsafe. At that point, no amount of sugar will trick them into eating it.
When Baking Soda Makes Sense
Baking soda is worth trying if you have a small number of sugar-feeding ants, you want a pet-safe option (baking soda is nontoxic to dogs and cats in small amounts), and you’re comfortable with partial results. It’s a reasonable first attempt for a minor ant problem in a kitchen or bathroom.
It’s not the right tool for large infestations, carpenter ants, fire ants, or any situation where ants keep coming back after repeated treatment. For those cases, borax-based baits offer better colony-level control, and persistent problems with structural species like carpenter ants typically require professional treatment to locate and eliminate the nest.