Getting rid of ants comes down to three things: eliminating what’s attracting them, sealing how they’re getting in, and choosing the right treatment to wipe out the colony rather than just the ants you can see. Most people reach for a spray, but that’s often the least effective option. A well-placed bait can reduce ant numbers by 87 to 95 percent within a few weeks, while sprays only kill the workers that walk through them.
Why Sprays Often Make Things Worse
The instinct to grab a can of spray and blast every ant in sight is understandable, but it usually backfires. Surface sprays only kill the workers that physically contact the treated area. The queen, the brood, and the thousands of ants still inside the nest are completely unaffected. Worse, many spray insecticides are repellent, meaning they don’t kill ants so much as reroute them. The trail you sprayed disappears, but the ants find a new path to the same food source, sometimes splitting into multiple trails where there used to be one.
Spraying near bait stations is an especially common mistake. The spray residue contaminates the bait and repels ants away from it, undermining the one method that actually reaches the colony.
How Baits Eliminate the Whole Colony
Ant baits work on a simple principle: worker ants find the bait, carry small amounts back to the nest, and feed it to the queen, the larvae, and other workers. This is why baits are deliberately slow-acting. If the poison killed workers immediately, they’d never make it home. Instead, the toxin spreads through the colony over days or weeks until it collapses.
Research on Argentine ants, one of the most stubborn species, showed that both gel baits and granular baits reduced ant numbers by 71 to 91 percent within the first week. By week four, reductions hit 87 to 93 percent, and by week eight, some treatments achieved 95 percent reduction. That kind of result requires patience. You’ll see ants swarming the bait for several days, and that’s exactly what you want.
For the best results, place bait stations along the trails ants are already using. Don’t clean up the trail first, and don’t spray anywhere near the bait. Let the ants do the work of carrying the poison home. If the bait isn’t attracting ants within a day or two, try switching between sugar-based and protein-based options. Ant dietary preferences shift with the season and the colony’s needs.
Diatomaceous Earth as a Chemical-Free Option
Food-grade diatomaceous earth is a fine powder made from fossilized algae. It kills ants through a purely physical mechanism: the microscopic sharp edges scratch the waxy outer layer of the ant’s exoskeleton, causing it to lose moisture and dry out. It contains no chemical toxins and remains effective indefinitely as long as it stays dry and undisturbed.
The practical catch is that diatomaceous earth only works on contact, so it won’t reach the colony the way bait does. It’s best used as a barrier. Dust it lightly into cracks, along baseboards, behind appliances, and in wall voids where ants travel. A thin, even layer works better than heavy piles, which ants will simply walk around. Once it gets wet, it stops working entirely, so it’s mainly useful indoors or in protected outdoor areas.
Cut Off Food, Water, and Entry Points
No treatment works long-term if your home keeps inviting ants back in. Ants are scouting for two things: food and moisture. Eliminating both is the single most effective prevention strategy.
On the food side:
- Store sugar, honey, syrup, and pet food in sealed containers, and wipe the outside of those containers clean so residue doesn’t attract scouts.
- Clean up grease, crumbs, and spills immediately, especially in kitchens. Even a thin film of grease on a stovetop is a food source.
- Rinse out cans and bottles before recycling. Empty soft drink containers are magnets for ants.
- Take garbage out daily and clean the bin itself regularly.
- Check outdoor plants near the house. Aphid-infested shrubs produce a sweet secretion that ants feed on, and ripened fruit on trees draws them in too.
On the moisture side, fix leaky faucets and dripping sprinkler heads. Ants are drawn to water, and kitchens and bathrooms are common hot spots precisely because of the plumbing. Check under sinks, along pipes, and near any area where condensation collects.
For entry points, follow ant trails backward to find where they’re coming into the building. Ants prefer to travel along structural elements like wires, pipes, and the edges of foundations. Caulk every crack and gap you find, paying extra attention to where utility lines enter the house. Even small crevices around window frames and door thresholds are enough for ants to exploit.
Identifying Carpenter Ants
Most household ants are a nuisance. Carpenter ants are a structural threat. They don’t eat wood the way termites do, but they tunnel through it to build nests, and a mature colony can cause thousands of dollars in damage before you realize they’re there.
Signs to watch for:
- Small piles of fine wood shavings near wooden structures, almost like sawdust.
- Rustling or crinkling sounds inside walls or hollow wood.
- Winged ants indoors during spring or early summer. These are reproductive ants from a mature colony that’s ready to expand.
- Visible ants during daytime. Carpenter ants are mostly nocturnal, so daytime sightings often mean the colony is large and nearby.
- Moisture-damaged wood anywhere in the home. Carpenter ants specifically target softened, damp wood as their preferred nesting material.
If you’re seeing these signs, DIY methods are unlikely to be enough. Carpenter ant nests are often deep inside wall voids, subfloors, or structural timbers where baits and dusts can’t easily reach. Professional inspection typically costs $100 to $300, and treatment runs $300 to $1,000 depending on the size and location of the infestation. Structural repairs, if the colony has been active for a while, can run $2,000 to $5,000 or more.
Keeping Pets Safe Around Ant Products
Dogs are the bigger concern here. Many ant baits use sweet attractants, and dogs are drawn to them for the same reason ants are. Cats tend to be pickier eaters and rarely consume bait directly, but they can pick up residue by walking across treated surfaces and then grooming their paws.
The most important safety distinction is the type of insecticide. Products containing boron compounds are relatively low-risk for pets in small amounts, though large quantities can cause serious stomach upset and kidney problems. Pyrethroid-based sprays and baits are a bigger concern. Cats are highly sensitive to pyrethroids and can develop neurological symptoms from small exposures. If you have cats, avoid pyrethroid products entirely.
Rabbits face a specific risk from products containing fipronil, a common insecticide in ant treatments. Even small exposures can be life-threatening for rabbits. Dogs can also be at risk from eating the plastic bait station packaging itself, which can cause intestinal blockages. Place bait stations in spots pets can’t reach: behind heavy appliances, inside cabinets, or in narrow gaps along walls. Store all products in a locked or elevated area between uses.
When DIY Treatments Aren’t Working
Some species are genuinely difficult to control on your own. Argentine ants form supercolonies with multiple queens, meaning the colony can survive even if you kill one queen. If you’ve been baiting consistently for several weeks and ants keep returning, or if you’re dealing with carpenter ants, a professional pest management service can locate nests you can’t access and apply targeted treatments in wall voids, foundations, and outdoor perimeters. The combination of professional perimeter treatment with indoor bait stations tends to produce the most durable results for severe infestations.