The fastest way to get rid of ants is to use bait that worker ants carry back to the colony, killing the queen and the rest of the nest over one to three weeks. Spraying visible ants with contact killer feels satisfying but only removes the foragers you can see, leaving thousands more in the colony ready to replace them. Baiting works because it turns the ants’ own food-sharing behavior against the entire colony.
Why Baiting Works Better Than Spraying
An ant colony can contain tens of thousands of workers, and the ones trailing across your kitchen counter represent a tiny fraction. Killing those foragers with a spray does nothing to the queen, who keeps producing new workers from deep inside the nest. Within days, new trails appear.
Bait takes a different approach. Worker ants find the bait, eat it, and carry it back to share with nestmates and the queen. Because the active ingredient kills slowly, the bait circulates through the colony before ants start dying. Some ingredients prevent ants from converting food into energy. Others disrupt nerve signaling. Insect growth regulators don’t kill adult ants at all but instead stop the queen from producing viable eggs, collapsing the colony over weeks. One ingredient, indoxacarb, is actually activated inside larvae after workers feed it to them, and can kill a colony within three days.
The tradeoff is patience. You’ll typically see ants for a week or more after placing bait, and full colony elimination can take several weeks. Resist the urge to spray near your bait stations. Sprays repel ants and can keep them from finding the bait in the first place.
Choosing the Right Bait for Your Ants
Not all ants want the same food, and the wrong bait gets ignored. Most common household ants strongly prefer sugar-based baits, but protein matters too. Odorous house ants, the small dark ones that smell like rotten coconut when crushed, consistently prefer sugar and protein over fats. They’re especially attracted to sucrose solutions at about 20% concentration. Carpenter ants shift their preferences seasonally, favoring protein-rich food in early summer and switching to carbohydrates by late August. Argentine ants, common in warmer climates, overwhelmingly prefer liquid sugary baits and actually eat less when protein is added to sugar solutions.
If you put out bait and ants ignore it, switch to a different formulation. Try a sugar-based gel or liquid bait first, since most species respond to sweets. If that doesn’t work, try a protein-based bait with peanut butter or a grease-based formula. Placing both types simultaneously covers your bases.
Making Your Own Bait With Borax
A simple homemade bait combines borax (or boric acid) with something sweet. Borax is a slow-acting stomach poison, which is exactly what you want: slow enough for workers to share it before dying. Commercial ant baits use borax concentrations around 5%, and that’s a good target for DIY versions too. Higher concentrations kill foragers before they make it back to the nest.
For a liquid bait, dissolve sugar in water and add borax to reach roughly a 1% concentration. Set it out in shallow bottle caps along ant trails. For a solid bait, mix peanut butter with a small amount of borax and place it on pieces of cardboard. Liquid borate baits at 0.5 to 1.0% concentration have the most impact on the colony, though they need to be refilled regularly and may take a week to show results.
If you have pets or small children, place baits inside enclosed stations or in areas they can’t reach. Commercial bait stations are designed to let ants in while keeping larger fingers and paws out. The 5% borax concentration in most commercial products is relatively low, but keeping stations out of reach is still the safest approach.
Sealing Entry Points and Removing Attractants
Baiting handles the colony, but prevention keeps new colonies from moving in. Ants are scouting your home because they found food, water, or both. Cutting off those resources makes your home a less attractive target.
Start with sanitation. Wipe down counters after meals, store sugar and honey in sealed containers, and don’t leave pet food bowls out overnight. Even small crumbs behind a toaster or a sticky spot on the floor can sustain a trail of foragers. Fix leaky faucets and pipes, since many ant species are drawn to moisture as much as food.
Then seal the paths they’re using to get inside. Follow ant trails back to their entry point, which is often a crack around a window frame, a gap where pipes enter walls, or a space under a door. Caulk gaps in foundations, around utility lines, and along window frames. Weather stripping under doors closes another common route. Trim tree branches and shrubs that touch your house, since ants frequently use vegetation as a bridge to upper floors.
Diatomaceous Earth and Natural Options
Food-grade diatomaceous earth is a fine silica-based powder that damages the waxy coating on an ant’s body, causing it to dehydrate and die. It works as a physical barrier rather than a chemical poison, which appeals to people avoiding synthetic pesticides. However, it has real limitations: it’s not very effective when the soil is moist, and it rarely eliminates colonies when used alone. Think of it as a supplement to baiting, not a replacement. Dust it into cracks, behind baseboards, and along dry entry points where ants travel.
Essential oils get a lot of attention as natural ant repellents, but their effectiveness varies dramatically by type. In controlled testing against carpenter ants, clove oil showed about 88% repellency over 72 hours, performing close to commercial repellent products at 97%. Peppermint oil was moderately effective at around 56%. Tea tree oil was nearly useless, averaging under 9% repellency. These oils can discourage ants from crossing a treated area, but they evaporate and need frequent reapplication. More importantly, repelling ants doesn’t kill the colony. If you block one path, they’ll often find another.
What to Do About Carpenter Ants
Most household ants are a nuisance. Carpenter ants are a structural concern. They don’t eat wood like termites, but they excavate it to build nests, and over time they can weaken beams, window frames, and wall studs. Signs include small piles of sawdust-like shavings near wood surfaces, faint rustling sounds inside walls, and large black or dark brown ants (about half an inch long) appearing indoors, especially at night.
Carpenter ants nest in damp or decaying wood, so moisture problems are almost always involved. Fixing the moisture source is as important as killing the ants. Baiting works on carpenter ants, but because their nests can be deep inside wall voids or structural timber, locating and treating the nest directly sometimes requires professional help. If you’re seeing carpenter ants regularly inside your home, especially winged ones in spring, the colony is likely nesting in the structure itself rather than just foraging from outside.
A Practical Timeline
Expect to see fewer ants within 5 to 10 days of placing bait. Full colony elimination takes one to several weeks depending on the product and colony size. Growth regulators work the slowest, sometimes taking months, but they prevent egg production for up to a year after application. If you’re still seeing heavy ant traffic after two weeks of baiting, the colony may be very large, or you may need to switch bait types to match what the ants actually want to eat.
For lasting results, combine all three strategies: bait to destroy the current colony, seal entry points to block new invasions, and maintain clean, dry conditions so your home stops attracting scouts in the first place.