Although many ant varieties can cause problems in a home, few are as potentially damaging as the carpenter ant. This aptly named species builds its nest by tearing tunnels through wood. If left unchecked, this can wreak havoc on a building—resulting in thousands of dollars in damage. This is why it’s crucial to find a suitable solution that will eliminate the whole colony for good.
Carpenter ant killers offer a cost-effective alternative to hiring a professional exterminator to rid one’s home of destructive ants. These products come in various forms: sprays that kill on contact; liquid baits that attract and infect worker ants, which carry the poison back to their colony; and granules applied outdoors to prevent ants from getting inside. Use this buyer’s guide to find important considerations to keep in mind when shopping and recommendations for effective products to find the best carpenter ant killer for a pest problem.
- BEST OVERALL: Safer Brand Diatomaceous Earth Ant & Insect Killer
- RUNNER-UP: Eco Defense Biobased Pest Control Spray
- BEST BANG FOR THE BUCK: Mighty Mint Gallon Insect and Pest Control
- BEST BAIT GEL: Combat Indoor and Outdoor Ant Killing Gel
- BEST GRANULAR: EcoLogic Lawn and Yard Insect Killer Granules
- BEST SPRAY: Orange Guard Home Pest Control
- BEST OUTDOOR: Wondercide EcoTreat Outdoor Pest Control Spray
- BEST FOR NESTS: Garden Safe Diatomaceous Earth Insect Killer
- BEST ROACH & ANT KILLER: Ortho Home Defense Ant & Roach Killer
Before You Buy Carpenter Ant Killer
While there are effective solutions on the market for ridding one’s home of carpenter ants, it’s important to understand the risks associated with these products. Many insecticides contain such active ingredients as borax and hydramethylnon. These chemicals can cause vomiting and diarrhea or even kidney failure and seizures if ingested or inhaled. Borax is also unkind to the planet as it uses boron, extracted through strip mining, a process that leaves a large environmental footprint. Many chemicals commonly found in pesticides also harm aquatic organisms as well as beneficial insects, including honey bees, ladybugs, and spiders.
This guide focuses on products that are effective at controlling carpenter ant populations while leaving a much smaller footprint on the environment. They include products that use natural ingredients such as diatomaceous earth and essential oils, as well as repellents that won’t harm environmentally beneficial insects.
How We Chose the Best Carpenter Ant Killers
A good carpenter ant killer should be an effective and safe way to eliminate these wood-destroying insects from the home. With that in mind, we selected products with active ingredients proven to kill ants without harming people, pets, or the planet. All of our selections are deemed safe by the Environmental Protection Agency (EPA). Some are also USDA Certified Biobased, meaning they have ingredients derived from plants and other renewable materials and contain no harsh synthetic chemicals.
In addition to insecticides (i.e., insect killers), we also chose products that repel pests, reducing the impact on the environment by not killing beneficial insects. Where possible, we chose eco-friendly products containing all-natural ingredients that are nontoxic to people and pets.
Our Top Picks
The lineup below features pest control products capable of killing carpenter ants that make their way into a home; some may also be able to annihilate an entire ant colony in a matter of days. Our selections are effective while minimizing environmental impact.
For those looking to end their ant problem without introducing harmful chemicals into the environment, diatomaceous earth is an excellent option. This natural substance, which is safe for indoor and outdoor use, consists of the fossilized remains of microscopic aquatic organisms; it infiltrates the exoskeletons of ants, dehydrating them from the inside out and killing them in about 48 hours.
Diatomaceous earth is also an effective means of killing bed bugs, cockroaches, fleas, and other creepy crawlers. This product is not harmful to humans or animals, providing a safe pest solution for homes with pets and young children. Safer Brand’s diatomaceous earth comes in 4-pound bags.
- Type: Powder
- Active ingredient: Diatomaceous earth
- Quantity: 4 pounds
- Kills in 48 hours
- Doesn’t expire
- Suitable for indoor or outdoor use
- Powder format can be messy for indoor use
Get the Safer Brand carpenter ant killer on Amazon or at The Home Depot.
With ingredients that are safe for humans and the environment, Eco Defense is an effective and safe way to rid one’s home of carpenter ants and other pests. Eco Defense uses geranium and peppermint essential oils to kill ants along with fleas, earwigs, gnats, scorpions, and a host of other pests.
In addition to killing on contact, it also serves as a preventative to repel insects. The formula, which is USDA Certified BioBased, is considered safe for use indoors and outdoors with less concern about coming into contact with people or pets. Though effective, Eco Defense is one of the more expensive options on the market.
- Type: Spray
- Active ingredient: Geranium and peppermint oils
- Quantity: 16 ounces, 32 ounces, and 1 gallon
- Kills on contact
- Creates a barrier that repels pests
- Uses ingredients safe for humans and the environment
Get the Eco Defense carpenter ant killer on Eco Defense.
Mighty Mint is an affordable yet effective means of repelling carpenter ants without harmful chemicals, and it imparts a pleasant, natural aroma in the process. It relies on peppermint oil, which has a high concentration of menthol, to deter and drive off spiders, ants, and a variety of other pests effectively. Peppermint is nonlethal, so while it won’t kill ants, it won’t harm beneficial insects either. It is also safe to use indoors around people and pets.
- Type: Spray
- Active ingredient: Mint oil
- Quantity: 1 gallon
- Safe for people, pets, and the environment
- Easy to apply
- Won’t hurt beneficial insects
- Pleasant smell
Get the Mighty Mint carpenter ant killer on Amazon or at The Home Depot.
Combat incorporates crosshairs into its logo for good reason: This ant-killing gel comes in a syringe for precise, targeted application in cracks and crevices. While the active ingredient, fipronil, is not considered to be environmentally safe and should be kept away from people and pets, only a small amount in a tiny space is required to get the job done—and such a small amount is unlikely to have an impact on the wider world. The applicator also prevents the messy overspray that other products can cause, making it easier to limit its application to a small crack, minimizing potential contact with people, pets, and the planet.
Combat gel is capable of knocking out an entire colony because all it takes is one ant to come into contact with the gel and carry it back to the nest. Within a few days, the colony should be destroyed.
- Type: Gel
- Active Ingredient: Fipronil
- Quantity: .95 ounce
- Very small amount needed
- Can kill the entire colony
- Doesn’t make a mess
- Fipronil can harm the environment and should be kept away from people and pets
Get the Combat carpenter ant killer on Amazon or at The Home Depot.
To keep ants at bay where kids and pets are romping in the yard, consider these EcoLogic granules. The environmentally friendly formula consists of natural ingredients, including corn mint and geranium oil, to kill and repel a broad range of insects, including fleas, spiders, mosquitoes, cockroaches, and several species of ants.
EcoLogic will also kill beneficial insects, so it should be used responsibly with a spreader that will limit application to the lawn. Avoid applying EcoLogic in flower beds, where it has a greater chance of coming into contact with bees.
- Type: Granules
- Active ingredient: Corn mint, geranium oil
- Quantity: 10 pounds
- Environmentally friendly and nontoxic ingredients
- 1 bag treats 20,000 square feet
- Easy to apply with spreader
- Can also kill beneficial insects
Get the EcoLogic carpenter ant killer at The Home Depot.
An inherent problem with most spray pesticides is that the wide release of the product can cause tiny particles to become airborne—a hazard if they contain harsh or toxic chemicals. That’s not an issue with Orange Guard, which uses orange-peel extract as its active ingredient.
This formula makes Orange Guard one of very few pesticides appear on the FDA’s Generally Recognized as Safe List in regard to food. This rating makes Orange Guard safe to use in the kitchen and around people and pets. It also appears on the Organic Review Institute’s list of organic products. Orange Guard works as a pesticide when sprayed directly on insects and also as a repellent.
- Type: Spray
- Active ingredient: Orange-peel extract
- Quantity: 32 ounces
- Safe for use around food
- Safe for the environment
- Works as pesticide and repellent
- Needs more frequent applications than other pesticides
Get the Orange Guard carpenter ant killer on Amazon.
Pesticides designed for outdoor use aren’t generally an option where kids and pets are often at play. These products also pose a greater environmental risk than pesticides applied inside the home. Wondercide, however, is a nontoxic option that relies on a mix of natural essential oils, including sesame and cedarwood, to kill and repel ants, mosquitoes, fleas, and ticks, among other insects.
Wondercide comes in a spray bottle that attaches to a standard garden hose. The concentrated formula is automatically diluted as water from the hose passes through the attachment for easy application. A 32-ounce bottle can cover 5,000 square feet, and each treatment lasts between 30 and 45 days.
- Type: Concentrated hose attachment
- Active ingredient: Cedarwood and sesame essential oils
- Quantity: 32 ounces covers 5,000 square feet
- Easy to apply via a garden hose
- Uses essential oils as active ingredients
- Kills on contact
- Repels insects for up to 45 days
Get the Wondercide carpenter ant killer on Amazon.
This insect killer will take out a nest of carpenter ants without creating a hazard for the environment, people, or pets. It uses diatomaceous earth, which kills insects by infiltrating the cracks in their exoskeleton and then dehydrating them. To destroy a nest, use a squeeze bottle to blow diatomaceous earth into moist wood where carpenter-ant infestations typically start. To kill insects outside the nest, sprinkle the powder directly onto ant traffic areas.
Garden Safe kills within a day of contact. It’s nontoxic and safe for use in vegetable gardens. In addition to ants, Garden Safe will kill cockroaches, silverfish, beetles, and other insects.
- Type: Powder
- Active ingredient: Diatomaceous earth
- Quantity: 4 pounds
- Safe for use around food, pets, and people
- Effective for destroying ant nests
- Has no shelf life and will work indefinitely when kept clean and dry
- Powder can be messy if used indoors
Get the Garden Safe carpenter ant killer on Amazon or at Lowe’s.
This aerosol spray from one of the biggest makers of pest-control products is a safe choice for taking out roaches and ants inside the home. This kill-on-contact spray uses a mix of essential oils such as geranium, cinnamon, castor, corn mint, and clove that isn’t toxic to people, pets, and the environment.
It also won’t stain surfaces or fabrics, making it suitable for furniture and other living-area surfaces. Its aerosol-spray design allows it to be applied at all angles, making it easier to hit insects skittering across walls and ceilings or flying through the air.
- Type: Spray
- Active ingredient: Essential oils
- Quantity: 14 ounces
- Uses essential oils safe for the environment, people, and pets
- Easy to direct and apply
- Kills on contact
- Also works as an effective repellent
Get the Ortho Home Defense carpenter ant killer on Amazon.
Or, DIY Your Own Carpenter Ant Killer
There are several homemade remedies that are safe, cheap, easy to make, and effective against ants—and they use common household products likely to already be on hand in the kitchen cupboard.
- Spray a one-to-one solution of white vinegar and water on ants to kill them, and then use a paper towel to wipe them up. The lingering smell, which is not detectable to humans, will also repel other ants.
- To take out a nest, try pouring a pot full of boiling water over it. This will flood the nest and kill ants on contact.
- Kill ants on contact by sprinkling cornstarch over them, then pouring water on top to trap possible escapees. Wipe them up with a paper towel.
Diatomaceous earth is one of the most effective ways to control pests while having minimal impact on the environment, which is why Safer Brand carpenter ant killer is one of the best all-around carpenter ant killers. Those looking for a spray that will kill on contact should consider Eco Defense carpenter ant killer, which uses natural ingredients to take out a wide variety of pests, including ants.
What to Consider When Choosing the Best Carpenter Ant Killer
Understanding how the different types of pesticides and repellents work is key to addressing a carpenter ant problem. Ahead, learn more about granules, sprays, and gels, as well as other factors to consider when selecting the right product.
Like many ant killers, those specific to carpenter ants come in two basic types: baits and kill-on-contact insecticides. True to its name, the latter type of insecticide kills ants within seconds of contact. Kill-on-contact insecticides come in sprays and powders.
These products kill ants almost immediately. Many leave a residue that will kill or repel other ants that scurry through the substance days later. Although kill-on-contact products eliminate the immediate threat, they aren’t effective at destroying the colony unless sprayed directly onto an anthill.
A dry powder such as diatomaceous earth kills ants by infiltrating the cracks in the insects’ exoskeletons and dehydrating them, a process that takes up to a day.
Insecticide gels, which typically come in syringe-style applicators, allow the user to apply small doses into cracks where ant activity is observed. Gels typically take several days to kill ants. This delayed action allows time for infected ants to return to the nest and infect the entire colony. Although these baits don’t offer the instant gratification that sprays do, they have better long-term results by eliminating entire colonies.
Ant killers use a variety of active ingredients. Borax is a particularly popular pesticide; the substance is deadly to ants but presents a low level of toxicity to humans, making it suitable for indoor ant baits. Hydramethylnon is another common active ingredient that’s lethal to ants. Other active ingredients used in ant killer include indoxacarb, avermectin, lambda-cyhalothrin, and fipronil. While these ingredients are relatively safe for use around homes, they do present health hazards. More importantly, these chemicals can wreak havoc on the environment, especially if they find their way into aquatic environments.
There are pesticide alternatives that pose less risk to people, pets, and the environment. There are products that use essential oils from such natural sources as mint, cedarwood, cinnamon, and orange peels. Diatomaceous earth, which consists of the fossilized remains of tiny aquatic organisms, is also an effective way to kill pests by dehydrating them. There are environmentally friendly repellents that keep bugs away and don’t harm helpful insects, such as honey bees and ladybugs.
Ant killers come in several forms, each with a different application method and specific means of killing ants. Shoppers will want to consider whether they prefer ant-bait stations, granules, sprays, or dust based on the following characteristics:
- Bait stations are enclosed plastic receptacles with small holes that allow ants to enter, collect a liquid or gel bait, and then leave. An ant bait can take several days to kill, giving ants time to return to the colony and infect the population. Bait stations typically have liquid or gel ingredients that stick to the ants that enter.
- Granules are sprinkled on the ground, where they dissolve and leave a residue that kills ants on contact. Granules will treat the soil for several months and, when sprinkled to create a barrier around the home, prevent ants from getting inside.
- Sprays consist of a thin, sticky liquid that can be applied directly onto ants to kill on contact or to cracks and crevices where ants enter the home. Sprays leave a residue that infects and kills any ants that cross over it.
- Dust ant killers typically use diatomaceous earth. When ants crawl through it, the dust penetrates their exoskeletons and dehydrates them from the inside out.
Many of the active ingredients in ant killers pose no serious health risks to humans. However, consumers should still be careful when using any pesticides in or around the home. When using an ant killer, it’s essential to take precautions to limit and prevent exposure. Keep the following tips in mind for application:
- Always wear protective gloves when handling an ant killer.
- Don’t place baits in areas that are accessible to children or curious pets who may come into contact with them.
- Sprays and dust can be absorbed into the skin, so don’t apply them in high-traffic areas.
- Avoid treating areas where food is stored or prepared.
- When applying an ant spray, wear eye protection and direct the spray away from the eyes or any exposed skin.
Carpenter ant killers are effective at more than eliminating and controlling ant infestations. These multifunctional products can also take out a broad range of other common pests, including roaches, fleas, crickets, termites, and other insects. Most manufacturers list the types of insects the pesticide treats on the product container.
Many ant baits have additional features that make them suitable for use in different environments. Ant killers with syringe applicators facilitate targeted applications in areas such as the small cracks and gaps between baseboard molding that ants can infiltrate. This allows the user to treat the affected area without overspray, minimizing exposure to humans and pets.
Bait stakes have a time-release poison that will not only take out existing colonies but also prevent ants from arriving and establishing new ones. Outdoor bait stations have waterproof housing to prevent rain from coming into contact with the poison, thereby ruining the bait station.
Tips for Keeping Carpenter Ants Away Naturally
Although there are plenty of products that use chemicals to take out carpenter ants, there are also ways to keep carpenter ants at bay without using any pesticide at all. Carpenter ants are attracted to wet and rotting wood. Those who maintain their homes well and who repair damage as soon as it’s spotted are less likely to deal with carpenter ants.
Carpenter ants also like heavily wooded areas, so keep brush and tree limbs away from the home’s exterior. Likewise, make sure mulch and soil do not come into contact with the wood parts of the home. Cracks and crevices around the home’s foundation can serve as an entryway for carpenter ants. Sealing these gaps will make it harder for carpenter ants to find a way in.
- Repair leaks and water damage immediately.
- Keep brush and tree limbs off of the home.
- Don’t allow landscaping to come into contact with wood parts of the house.
- Seal cracks and crevices around the home’s foundation.
If you still have concerns about carpenter ant killers, read on for answers to some of the most commonly asked questions about these insects and products.
Q. What repels carpenter ants?
Carpenter ants use pheromones to create trails that other ants follow. You can disrupt this system of communication with essential oils that are effective yet safe for the environment. These include clove, lemongrass, peppermint, orange, and lemon oils, which confuse carpenter ants and prevent them from following the trail.
Q. Do carpenter ants go away on their own?
Once they’ve established a nest in damp wood, carpenter ants will not move away on their own. The nest will continue to grow and expand unless it’s treated, which can result in serious damage to the home and other structures.
Q. How do you treat a carpenter ant infestation?
There are several options for treating a carpenter ant infestation. Granules for outdoor use are an excellent way to eliminate colonies in the yard or create a barrier around the house. Liquid baits designed for indoor use are a good way to eliminate colonies by infecting worker ants who deliver the poison back to the nest.
Q. Will regular ant bait kill carpenter ants?
Although some ant bait can kill carpenter ants, check packing information to know exactly which species the product targets before making a purchase.
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