Best Carpenter Ant Killers Review. Top Ant Baits, Traps & Poisons

Author: Michael Potter Reviewed by | Expert opinion Updated: May 13, 2022

Carpenter ants, or Camponotus, build their colonies in wood. We will tell you how to find their nests and distinguish them from termites. You’ll know the best methods of getting rid of carpenter ants according to the scientists and find the 18 Best carpenter ant killers: poison baits, killer sprays, foams, and dusts.

What Is The Best Carpenter Ant Killer?

The most effective solution is placing baits as they will kill the entire colony, not just foragers. When choosing the right bait, you should opt for slow-acting baits because they give foragers enough time to spread the poison among other members of the colony.

If you have a severe infestation and you see ants swarming around your house, first apply a powerful insecticide to provide fast knockdown. After that, place baits close to their hiding sites to kill the queen(s) and the colony. Without doing that, all your efforts to eradicate ants will be futile.

1. Professional-Grade Advance Carpenter Ant Bait to Kill the Queen & Colony
The solution is based on Abamectin, a delayed-action insecticide. It can be used both indoors and outdoors. A great choice for large ants that are difficult to control.

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2. Maxforce Carpenter Ant Bait Gel for Indoor and Outdoor Use
This bait is very attractive to ants due to a high content of sugar and moisture. Its active ingredient Fipronil kills ants and larvae in 3-5 days by disrupting their nervous system.

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3. Termidor Foam to Treat Walls and Spray Deep Down the Nest
This Fipronil-based foam should be sprayed where ants hide. The colony will die within a day or two. The foam is dense and can also serve as an effective barrier.

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4. Bayer Advanced 700310 Carpenter Ant Killer Plus Concentrate to Treat Lawn and Mounds 
This 40-oz concentrate contains the active ingredient B-Cyfluthrin. It covers an area of up to 10,500 sq ft and is applied to lawns, foundations, woodpiles, patios, mounds.

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5. Suspend Sc Professional Insecticide for Fast Knockdown
This odorless concentrate is based on Deltamethrin. The 16-oz pint makes up to 64 gallons of spray. It can be used on porous surfaces and in food handling areas. Fast knockdown, high mortality and a long residual effect.

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6. Talstar 3/4 Gallon Pros Pest Control Insecticide
This highly effective insecticide contains 7.9% bifenthrin. Powerful, economical, safe, and odorless, it is widely used by professionals for ant treatment. The concentrate can be mixed at a rate of .2 oz to 2 oz per gallon.

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If you are looking for the most effective treatment, combine professional insecticides like Advance and Suspend that are used by exterminators. Neither the carpenter ants nor other household pest insects will be able to withstand such measures.

Know The Enemy

  • Carpenter ants are black and fairly large (up to ½ inch). Usually, their appearance in the spring next to a tree or a structure of wood signifies the proximity of their colony.
  • Some may confuse them with termites, but carpenter ants are larger, have a different shape of antennae and body. Unlike termites, ants do not feed on wood but make a colony in it instead. Crushed wood is removed from trails and paths outwards. Sawdust can lie openly or be piled behind a wall.
  • Carpenter ants DO NOT create mounds in the soil. They settle in wet and dry wood preferring wet wood, which is why their nests can be found in living trees and wood, near water sources in bathrooms and around basins. They are not visible from the outside since the wood becomes fragile but retains its shape.
  • To find a nest, you can try screwing a hole with a screwdriver or knocking with a handle and listening as the ants will respond with a peculiar quiet rustle. Remember to never touch them with your bare hands as the workers have strong jaws and bite readily if they are handled.
  • Fortunately, carpenter ants are not as destructive to wooden houses and furniture as termites are, but the scale of destruction is not always visible since they create a maternal colony with a queen and thousands of workers and a few satellite ones with a large number of workers and no queen.

Expert Opinion: Les Greenberg, Ph.D. University of California Riverside

Les Greenberg, Ph.D. University of California Riverside

Les Greenberg, Ph.D., works at the Department of Entomology of the University of California Riverside. He is an entomologist, studying ants, primarily Argentine ants, and fire ants. Dr. Greenberg has multiple scientific publications on ant control, including articles on risks posed by urban-use pesticides, the efficiency of liquid bait stations, and many more.

Fipronil spray has become the preferred ant treatment used by pest control companies because it is very effective… There are reductions in ant numbers from fipronil and bifenthrin sprays. If you look at the blue line, you can see the percent reductions after the Termidor treatment, very good results. It is about 93% at some point. By adding Talstar granules to this treatment, we got even better results. Look at the blue lines again for eight weeks out — we are getting 90- to 93-percent control of ants. If you do just a Talstar or a bifenthrin perimeter spray, it typically results at an 81% reduction in a week. Now, I am looking at our bait stations with boric acid and imidacloprid. We are doing 73% control, which is pretty good… We have found that a 1-gal fipronil perimeter application is effective in controlling ants, giving an 80% reduction at 8 weeks. For both bifenthrin and fipronil, the results were poor when using spray-free-zones, less than 30% at 8 weeks.

Here are 4 potent insecticides that, according to Les Greenberg, produce the best results: Termidor, Talstar, Boric acid, and imidacloprid ant baits.

Labeled for ants and termites, the BASF 805571 Termidor Foam is based on fipronil. This product is recommended for spot treatments and should be applied to nests, voids, and other hiding places of ants. Within seconds, the foam quickly expands at a ratio of 30:1. The insecticide works up to 5 times faster than baits available on the market.

The second option, Talstar 3/4 Gallon Pros Pest Control Insecticide, is a liquid concentrate made with 7.9% bifenthrin. It kills ants on contact and boasts a long residual — over 3 months after treatment. Opted for by professionals, it is economical, safe, and odorless. Use the insecticide for perimeter treatments around the house or spray it indoors.

The TERRO 2600 FBA 2 lb. Perimeter Ant Bait is based on 5.0% orthoboric (boric) acid and is the safest method of ant control. One canister contains 2 pounds of weather-resistant granules, which should be applied along the house’s perimeter to prevent ants from entering inside. According to the manufacturer, this product can eliminate the entire colony.

The Maxforce Quantum 0.03% Imidacloprid Ant Control Liquid Bait comes with 10 stations and a 120-gram bottle. Labeled for multiple ant species, it has a delayed action, which allows for killing more ants. Unlike many other baits, this one lasts for up to 3 months as it doesn’t lose moisture long enough. The bait can be placed both outdoors and indoors, including food preparation areas. The bait is recommended as an effective way to remove the entire colony as well as eliminate ants in hard-to-reach areas.

Scientific Methods of Killing Carpenter Ants

The only way to get rid of carpenter ants is to destroy their nests. It is a difficult task given that their colony is usually located in a secluded spot.

To find their nest, feed the insects with something sweet, such as honey. Once an ant has taken the food, it will hurry back to its nest and you’ll be able to follow the trail.

The insect will hide behind the baseboard, in the closet or anywhere else where its colony is located. For complete extermination, it is crucial to penetrate into the void and the passages of the nest.

Using slow acting baits is the most effective way to destroy the colony. This is critical, because only about 10% of the ants are out foraging at any one time, and the remaining 90% are in the nest. The ants must be able to take a piece of poisoned bait and carry it to the nest to share with its co-habitants and the queen. Killing the queen means defeating the entire colony.

7 Steps to Destroy Carpenter Ant Nest

  1. Fix any roof or water pipe leaks, remove other sources of moisture, exclude contact of the wood with soil or mulch where possible, don’t let the trees touch your house, seal any holes and cracks in the foundation, especially around the wiring, and do not store firewood in the house or in the garage.
  2. Since ants have a “sweet tooth,” reducing the number of insects that produce honeydew (a substance secreted by aphids) might control ants around structures, as state the University of California specialists.
  3. Use boric acid. The University of Kentucky experts explain how it’s done: «Treat wall voids and other hidden spaces where ants are entering by carefully drilling a series of small (1/8 inch) holes and puffing boric acid into the suspected nest areas. The boric acid powder will disperse in the hidden void and contact and kill the ants. If you suspect the nest is in a wall, drill and treat at least 3-6 feet on either side of where ants are entering to maximize the chances of contacting the nest».
  4. Just like with any other species, the food preference of the carpenter ants appears to change on a seasonal basis. The University of Ohio scientists are convinced that the larvae require protein-based foods, so it is more helpful to use protein-based baits for getting rid of larvae.
  5. Aerosol spray nest treatments can be effective. Insecticidal vapors can spread within the wood to penetrate inaccessible areas of the nest, aiding in colony eradication.
  6. Sticky traps are far less effective. Their use is justified only by the need to protect a specific object, for example, a fruit tree from the effects of insects.
  7. Carpenter ants are finicky so you’ll have to provide them with a wide variety of different kinds of poison baits: sugar and protein-based.

First attract them to a nontoxic food source like sugar milk, cherry or diced crickets or mealworms. After the ants start feeding, replace the nontoxic food source with several different poison baits, and let them choose the one they prefer.

The  University of Minnesota experts claim that carpenter ants are very fond of the protein-rich tuna, which is why they are so often seen eating cat food made of fish. Add some pieces of fish to the poison lying around and wait for the results.

How Do They Work?

Type Active Ingredients /


Best Use
Liquid insecticide


Bifenthrin, Gamma-cyhalothrin, Deltamethrin /

Kills on contact and creates a protective barrier around the house.

Use outdoors or indoors. Pour into mounds, treat foundations and spray in the insects’ activity areas.
Granular Bait


Acephate, hydramethylnon /

They destroy the colony and prevent new pests from appearing.

Indoor and outdoor treatment. Use outdoors for broadcast treatment, pour it around the mound and along the trails.
Foam and sprays


Fipronil /

Will kill an inaccessible colony within a few days.

To be sprayed on nests in the walls.
Poison baits (bait stations)


Fast-acting: Indoxacarb
Slow-acting: hydramethylnon, fipronil, boric acid (borax) /The most effective method that can eliminate the entire colony. It is effective within 3-5 days (fast-acting), 1-5 weeks (slow-acting).
Use indoors or outdoors. Ants are finicky and they change their preferences often so you will likely have to switch bait types several times.
Diatomaceous Earth


Organic insect killer /

Contact action: the particles cut the insects’ exoskeleton and cause dehydration.

Use indoors, spray along the trails and in the insects’ activity areas.
Boric acid (dust)


Low-toxic insect killer /

Slow-acting stomach poison.

Use indoors, spray along the trails, down the cracks and shelters.


Pyriproxyfen /

Highly effective: sterilizes the queen and therefore will remove the colony completely.

A very slow-acting product (is effective at least after a month), so be patient.


7.9% Bifenthrin /

Kills ants on contact and has a long residual. It keeps on killing ants for over 3 months after application.

Use indoors and outdoors, around homes, hospitals, schools, and food processing facilities. It is good for perimeter treatment and can be applied around ornamentals.

Top Best Carpenter Ant Killers

There are many universal insecticides available on the market suitable for dealing with ants, but not all of them are helpful against carpenter ants.

We have selected 18 organic & insecticidal products that contain active ingredients recommended by scientists: Diatomaceous Earth, borax, abamectin, fipronil, hydramethylnon, bifenthrin, cyfluthrin, cypermethrin, deltamethrin, lambda cyhalothrin, permethrin, carbaryl (Sevin), diazinon, and chlorpyrifos.

Carpenter Ant Baits (Poisons)

Poison baits are most effective. They work as follows: a worker ant picks up poison to contaminate the entire colony including the queen.

Terro sells best-selling baits, but other brands use different ingredients that are also recommended by the entomologists: Maxforce by Bayer (fipronil), Advance (Abamectin) and Amdro (Hydramethylnon). Ants are very finicky so you’d better buy a few different baits to match the various tastes of fastidious carpenter ants.

1. BASF 396153 Advance Granular Carpenter Ant Bait

This fishy bait is based on delayed-action insecticide Abamectin. Once in the digestive tract, abamectin depresses the pests’ neuromuscular activity: “Visible activity, such as feeding and laying the eggs, stops shortly after exposure, though death may not occur for several days” (IPM).

These granules can be used both indoors and outdoors for removing carpenter ants as well as Acrobat, Bigheaded, Pavement, and other ants.

Sprinkle the bait in the ants’ activity areas and check where they carry it to find even several nests at once. The users recommend combining Advance with Maxforce as it is the combination of different baits that will lead to the best results.

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2. Maxforce Carpenter Ant Bait Gel-1 (Bayer)

This fipronil-based bait comes in a syringe and is made for eliminating carpenter ants. They love sugar and moisture, so Maxforce is most saturated with them for better attraction. Just like other liquid baits, this gel should be placed in the areas of activity of ants and near the nest.

The product can be used both indoors (including hospitals, restaurants, schools and other public places) and outdoors. Fipronil is relatively slow-acting poison, so the effect can be expected in about 3-5 days.

Carpenter ants are very fond of tuna, so they can often be found eating cat food made of fish. The users give valuable advice on making the sugar-based Maxforce bait as effective as possible: you need to lay some tuna leftovers in the right places and you will get a combo-bait. Read all customer reviews to find more tips about using it.

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3. Borax-Based Terro Liquid Ant Bait

The active ingredient of Terro Ant Killer, sodium tetraborate decahydrate (borax) as one of the insecticidal baits that have shown promise in controlling carpenter ants.

Poison bait contains borax (boric acid) that acts as a slow-acting stomach poison. Once it reaches an ant’s digestive system, it impacts metabolism and interferes with the absorption of nutrients, causing death by starvation.

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TERRO T300B Liquid Ant Bait Ant Killer: Check the current price

Terro outdoor baits contain the same active substance, borax, but the traps have been adapted for outdoor use. The product is sold in packs of 6 poison bait stations. A station should be installed in the ground or on the surface. The customers commend this bait. It is available as stakes that are pinned to the ground as well.

Terro Outdoor Baits Check the current price

Terro Outdoor Stakes  Check the current price

4. AMDRO Kills Ants Bait Stations

A pack contains 4 stations with hydramethylnon-based baits. They are slow-acting baits, meaning that the chance of killing not only workers but also the queen is very high.

According to the manufacturer, the process will take about two weeks. The stations are for indoor use only as they can work for three months and should be replaced with new ones when necessary.

This might seem too long for some, but the scientists name slow-acting baits as the most effective means of getting rid of ants. It is quite economical as well as a single bait station. In addition, the manufacturer guarantees a refund in case the product proves ineffective.

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Professional Insecticides

5. Bayer – 4031982 – Suspend SC -Insecticide

A pint of the product containing 4.75% deltamethrin. The insecticide is to be dissolved in loads of water (up to 64 gallons), so you’ll spray a large area with it. It can be used both inside and outside.

The product is odorless and highly rated by the customers. Experienced homeowners spray the foundation and entrances, such as doors, windows, and cornices and forget about the existence of the carpenter ants.

They recommend that you not relax though and to watch the trees outside as they can easily become the hotbeds of carpenter ants. They can penetrate the house even through the roof if any tree branches touch it. Read over 700 customer reviews to learn more.

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6. Talstar 3/4 Gallon Pros Pest Control Insecticide

This universal insecticide contains 7.9% of bifenthrin, a powerful pyrethroid that promises to deal with over 75 insect species. It is sold as a concentrate that should be mixed with water.

The product will act for up to three months provided it is properly used on dry surfaces both indoors and outdoors.

Talstar’s high rating is fully justified as the users recommend spraying the foundation of the building along the outer perimeter to create an additional killing barrier against the ants attempting to penetrate the house. Read other customer reviews to find more helpful tips.

Caution! This insecticide is toxic for aquatic plants and animals; you shouldn’t use it near bodies of water. When spraying it, wear protective gloves and avoid contact with skin and mucous membranes. Once the treated surfaces are dry, they become safe.

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Best Concentrated Insecticides and Sprays

7. Bayer Advanced 700310 Carpenter Ant and Termite Killer Plus Concentrate

If you have noticed some carpenter ants outdoors that have not yet penetrated your house, then this concentrated B-Cyfluthrin-containing insecticide will help them kill on contact and 75 other types of insects and protect your house from infestation.

It is to be dissolved in water and applied on lawn, landscape, foundation, trench, deck and patio, wood piles, and home structures and poured down a mound. This is a very economical option as a 32 oz bottle will be enough to cover 21,000 sq ft for lawn pest treatment and 10,500 sq ft for wood destroying pest treatment.

Such powerful treatments are not very popular with regular people, but those who have had a chance to test it, claim that it kills pests and can even serve as a preventive measure: Some users complain that treatment takes too long, though.

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8. Ortho Home Defense MAX Insect Killer for Indoor & Perimeter RTU Wand

This insecticide contains bifenthrin, which is a fast-acting component and a 1.1 canister. It is ready to use on a dry surface or down the nest.

The product is lethal for over 130 insect species, including carpenter, fire, lawn, argentine, pavement, pharaoh, pyramid, and red/western harvester ants. In addition, Ortho creates a barrier protecting your house for up to a year, and the lot for up to three months.

Judging by the reviews, it can reduce the number of ants in a day, but you may resort to repeated applications if necessary because a survived queen can revive the colony.

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9. Spectracide Triazicide Insect Killer For Lawns & Landscapes Concentrate

This ready-to-use spray contains such active ingredients as gamma-cyhalothrin and should be attached to a hose for spraying. The manufacturer claims that this spray kills over 250 insect species including ants.

As the customers state, the product doesn’t act on all types of insects, but it works against carpenter ants as the spray ensures up to three months of residual control. The product is for outdoor use only.

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10. Sevin Concentrate Pest Control

This must be the most eco-friendly insecticide listed (it contains Carbaryl) as it can be used for removing over 100 insects and sprayed even on vegetables, fruit, and ornamentals.

Its active ingredient, Carbaryl’s, advantage is that it does not accumulate in humans’ or pets’ bodies and is harmful even for small pets, such as rabbits. A concentrated liquid should be dissolved in water and used for treating contaminated trees and wooden structures with a sprayer.

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Carpenter Ant Spray, Foam and Dust

Aerosol sprays, foams, and dusts that could be sprayed deep down the nest are most effective against carpenter ants. Such products act as fast-acting poisons killing on contact.

Best Foams and Dusts

11. TERRO T1901SR Carpenter Ant & Termite Killer-2 Pack

This killer spray’s active ingredients are chemicals-pyrethroids: tetramethrin and deltamethrin.

A thin and long nozzle will allow spraying this foam type of liquid deep into the wall cracks, corners, hard-to-reach places, and holes in wooden structures where insects have already settled, and directly into the nest itself.

Terro promises to ensure not only a quick killing effect but also residual control over carpenter ants and termites for up to four weeks – and the users confirm this.

Use Terro both indoors and outdoors even if the pests have infested the trees in your garden: just spray the trunks around the whole circle with this spray and pour it into the holes filled with ants.

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12. BASF 805571 Termidor Foam Termiticide/Insecticide

Termidor Foam is a universal fipronil-based wood destroying insect treatment that is effective against carpenter ants, termites and other pests. Similar to other products, this foam is to be locally sprayed in the area of the insects’ activity, wooden holes and deep down the nest.

An ant colony can die of foam action within a day or two. Moreover, it is very dense and the ants won’t be able to overcome this barrier and survive. Although the product is quite expensive, users unanimously accept that it is effective and more affordable than hiring professional exterminators. Its 4.7 out of 5 stars rating can prove this.

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13. TERRO T600 Ant Dust – Kills fire ants, carpenter ants, cockroaches, spiders

A deltamethrin-based (a fast-acting rainproof component) waterproof dust is yet another product of the Terro line. It is versatile as it promises not only to remove carpenter ants but also to kill on contact boxelder bugs, cockroaches, crickets, firebrats, spiders, ticks, wasps and silverfish.

It can be applied anywhere where there are pests (both indoors and outdoors) and on any entrances to your house. To avoid making a mess, use a paint brush or a duster such as Harris Powder Duster.

The product is popular as it is one of the most accessible contact poisons and most of the users are satisfied with its effect.

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Natural & Organic Carpenter Ant Killers

14. Safer 51703 Diatomaceous Earth-Bed Bug Flea, Ant, Crawling Insect Killer

Diatomaceous earth is a universal non-toxic control product for insects and arachnids. The remains of diatom algae are crushed to a certain size when they turn into an acute insecticidal weapon.

The edges of the particles of diatomaceous earth cut the chitinous cover of the insect and damage it, causing the strongest lethal dehydration.

The product is safe for humans and pets and is not capable of damaging their skin. It is sold in a 4-pound package. Sprinkle the places of congestion and migration of ants with this powder.

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15. Zap-A-Roach Boric Acid Roach and Ant Killer – Odorless and Non-Staining

A boric acid tube is yet another traditional treatment. Two 16-oz boric acid tubes. This acid has long been used as an antiseptic in medicine. Over time, the remedy has been replaced by stronger antiseptics, and boric acid was still used when getting rid of ants.

It acts as a slow-acting stomach poison. The powder is placed in the cracks, behind the skirting boards, and sprayed through the nest entrances.

The boric acid powder is a real homemade ant treatment that has been used for ages because it is cheap, simple and quite effective. Still, keep in mind: whilst the working ants will bring the powder on their legs to the nest, there is no guarantee that it will reach the queen.

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16. Majestic Pure Clove Essential Oil- Pure and Natural

Clove essential oil is not an insecticide, but the scientists have confirmed its insect-repelling properties caused by its active ingredient, eugenol.

Clove oil is to be dissolved in a moderate amount of water and sprayed in places where there are many ants. Remember to shake the mixture regularly so that the oil remains afloat. Caution! Essential oils can be hazardous for pets, especially cats, pregnant women, and small children. Don’t use pure oil.

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Carpenter Ant Killers Comparison Chart

View Comments

  • Yesterday I found in my garden some kind of ants. They were large, probably 2 times more than termites, so I immediately rejected the theory that it was them, a large decorated belly (in stripes). I came across this article and came to the conclusion that this carpenter ants. The thing is that they chose one of my favorite trees, and this worries me, because, I understand, they destroy it eventually, but I do not want it at all. Tell me how to get rid of carpenter ants?

Author: Michael Potter Reviewed by | Expert opinion Updated: May 13, 2022
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Michael Potter, Ph. D. In biology, is a consultant and author for He is a scientist obsessed with the idea to save the world from pests.

He does not belive hollow words and empty promises from the producers ads. It is only facts that matter to him. Mr. Potter questions any statement and analzes in detail all related information.


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