7 Best Carpenter Ant Killers – Baits, Sprays & Granules

Updated on by Jared Belson | Please note that there may be affiliate links on this page.

Carpenter ants are among the biggest, most enduring, and fastest reproducing ants that can plague the average homeowner. So, whenever someone asks me about the best carpenter ant killers, baits and sprays are always my top two recommendations to deal with colonies swiftly and efficiently.

If you live in an area with rich vegetation or if moisture buildups are common around your home, you might want to start considering the following ant killers before ants start seriously damaging your property.

7 Best Carpenter Ant Killers to Kill them Quickly

If you’re dealing with very serious carpenter ant or termite infestations, I recommend grabbing a bottle of the Taurus SC. This is one of the most potent formulas out there. And, while highly toxic to ants, it won’t kill on contact. This means that it will reach the queen no matter how far deep she’s nesting.

The main active ingredient is Fibronil. This chemical isn’t very toxic to pets, if it’s in low concentrations. However, the Taurus SC formula has 9.1% Fibronil, so you may want to restrict its use to outdoors.

This insecticide doesn’t repel carpenter ants, instead it allows them to touch it, eat it, and then spread it throughout the colony. It has a pleasant scent for humans and it’s almost untraceable to the targeted pests.

I also recommend this product if you’re trying to deal with other infestations, such as cockroaches, centipedes, black widows, beetle grubs, and even house crickets.

  • Great for pre and post-construction treatments
  • Very efficient formula
  • Targets a wide range of pests
  • Almost odorless
  • Not available in all states

Terro insect killers enjoy a high success rate and have a large following among homeowners as a result. The spray is formulated to target carpenter ants, termites, wood wasps, and even carpenter bees. It’s fast-acting and can deal with an infestation quickly.

This powerful spray will kill ants on contact and keep on killing strays for up to a month. This counts as good residual control, especially in this price range. I also recommend this particular spray for its two-way nozzle. The design allows you to get it into tight spaces and narrow crevices where carpenter ants are likely to have set up their nest.

However, you may need to use a large amount of spray if you want it to reach the queen, as this is not a broadcasting formula. The good news is that the nozzle extension will allow you to reach deep into the crevices.

Because the formula is long-lasting and fast-acting, you can use it indoors and outdoors with equal efficiency. It’s also odorless and non-toxic, so it won’t cause adverse reactions for you or your pets. But what’s perhaps even more convenient is that it’s non-staining.

  • Kills quickly after contact
  • One-month lingering effect
  • 2-way nozzle
  • Doesn’t stain
  • Hard to reach the queen

The Terro 1806 baits are basically pre-filled bait stations which use borax as the main active ingredient. There are two ways to apply the baits, depending on where you need them. If it is inside your home or garage then you can simply leave them on the ground in areas with high ant traffic.

You can also place the baits in the ground. Terro includes stakes in this kit which you can use to drive the baits into the ground, placing them closer to the colony. Note that the trap will still be on top, but with the stakes you’ll provide the 1806 bait stations good stability and they’ll be able to resist bad weather conditions.

Although it is possible to use these bait stations inside and outside, I recommend them for outdoor use. That’s because you can keep your pets inside until you’ve dealt with the infestation. The slow-acting formula may take a few days to completely kill off an entire colony, depending on how quickly it reaches the queen.

  • Slow-acting formula
  • Can be used indoors and outdoors
  • Good weather resistance
  • Easily spread
  • Not completely safe around pets

Although this carpenter bait gel requires a larger initial investment, you are getting four tubes. This may be an ideal deal for those that need to deal with multiple colonies. Each 30g tube can destroy several colonies, but the amount you should apply to each may differ depending on how deep the ant queen is burrowed.

The main active ingredient in the Syngenta Optigard ant bait gel is a broad spectrum insecticide called Thiamethoxam. It is known to affect animals too, if they’re exposed to it in large quantities. Therefore, I recommend it for use in commercial and industrial areas.

That’s not to say that you can’t use it around your home if you’re careful with the application and restrict your pets’ roaming area for one or two days. The formula works like most other gel baits. Once picked up by worker ants, it then travels with them back to the nest and eventually infects the queen.

  • Easy application
  • Great for hard-to-reach places
  • Slow-release poison
  • Broad spectrum active ingredient
  • Slightly expensive if you only have a couple of colonies

If you want to deal with carpenter ants outside your home, the Amdro Ant Block bait granules may offer a very good solution. These granules are formulated to kill carpenter ant colonies quickly and efficiently. They can also provide a barrier so that ants won’t get even close to burrowing in your home.

The granules are effective against more than 20 ant species and offer residual control and protection for up to three months. Unless, of course, they get hit by heavy rain. You can apply the granules easily using the shaker. One or two shakes in high traffic areas should do the trick.

The formula is slow-acting or time-released. There’s no need to worry whether the granules will reach the queen or not. I also recommend opting for the 24oz shaker instead of the 12oz shaker, just to be on the safe side. The 24oz shaker should be enough to cover and treat up to 1,080 linear feet.

For the average home, that’s a pretty efficient barrier that can last months at a time. Just make sure to create a wide enough of a barrier and you’ll be fine.

  • Good water resistance
  • Time-released formula
  • Easy-to-use shaker bottles
  • Can cover up to 1,080 linear feet
  • Not for indoor use

If you’re looking for something affordable but also quite potent and also effective against other insects, then you might want to give the BioAdvanced 700335 a try. This spray has been formulated to work on most wood-infesting insects.

The formula works best when used on lawns, foundations, patios, wood piles, and other areas around your property that might be infested with carpenter ants. Considering that you can get this ant killer in 1.3 gallon bottle sprayers, you’re getting a good deal too.

Another reason why I recommend this is because the bottle has an electric sprayer. It makes formula application a lot easier and more consistent. Just keep in mind that this is a kill-on-contact carpenter ant killer.

It doesn’t have residual control properties or broadcasting properties. This means that in order to kill the queen you’ll have to stick the sprayer a bit deeper in high-activity crevices.

  • Electric sprayer
  • Consistent application
  • Kills ants fast
  • Works on many wood-infesting insects
  • May be difficult to kill the queen

This carpenter ant killer comes as a gel in 27g or .9 fl. Oz. tubes. Its formula targets a wide range of insects, including carpenter ants. I recommend using up to 1g in each place where you’ve noticed prominent ant activity.

The main active ingredient in this formula is Fipronil – it’s found in 0.001% concentration. This insecticide attacks the nervous system of ants and various other insects. Although safe to use inside crevices, it is known to cause some harm to birds and rabbits too. If you don’t let your pet rabbit come in contact with it, then it should be just fine.

Because it is also known to disrupt natural behavior of bees, I recommend using the Bayer Maxforce gel only inside the house. You can use it to fill some small holes and crevices in the wood where you spot carpenter ants.

It will kill ants relatively quickly, but you should know that the gel also has some broadcasting capabilities.

  • Easy to use
  • Safe for most pets
  • Can treat up to 27 affected indoor areas
  • Efficient Fipronil-based formula
  • Not suitable for outdoor use

Most Efficient Carpenter Ant Killers

Here are the reasons why I’ve put baits and sprays as the top solutions for carpenter ant infestations. Baits are highly effective because they contain ingredients which attract ants. They also have slow-acting poisons, borax or others, that don’t kill the ants instantly. Instead, the poisoned worker ants will carry the bait all the way back to the queen.

Killing the queen disrupts the entire colony and the reproductive cycles of ants. You shouldn’t think that fast-acting means that it would take days or weeks for the ants to die. It only needs enough time to reach the queen before it really starts working.

Sprays are also efficient, although you may need to use them in larger quantities. Besides, most people tend to use sprays as repellents, not so much as the main ant killer. Used in combination with granulated baits, this might give you the best chance of killing all potential strays and preventing future infestations in and around your house.

Slow and Steady Wins the Race

A slow-acting poison is often not enough. You should combine it with other methods.

How you use your ant killer product of choice is also important. When in doubt, always treat the nest as a hornet’s nest and avoid poking and prodding.

If you disturb a carpenter ant nest, the ants are likely to scatter which will make your ant killer far less effective. If only a few ants escape, they may be enough to start a new colony somewhere else in or around your house.

How to Use Various Ant Killers

Whether you’re using sprays or gels, always try to get them as deep as you can into the crevices where you’ve noticed carpenter ant activity. Granules and liquid baits should be placed near mounds, nests, and high-traffic areas.

You should also pay close attention to formulas with repellent properties. It’s recommended to use those outside your home in order to create a barrier around the house. Using repellents inside on crevices and noticeable tunnel entrances will likely just cause the ants to keep burrowing deeper, away from the repellent.

Are Electronic Sprayers Worth It?

Although in many situations I would normally recommend gels or foam ant killers, electric sprayer bottles also present an interesting alternative. For one, the application will be much more controlled and there’s less chance of wasting the product.

Secondly, some sprayers come with longer nozzle tubes and can reach deeper into a nest, thus making it easier to target the carpenter ant queen. That being said, not electric sprayers are made equal. Choose wisely if you opt for an electronic sprayer.

Dealing with State Laws

You may notice that not all carpenter ant killers, or pest killers in general, can be used everywhere in the country. Some products may be too toxic and you won’t be allowed to use them in certain states. States like Hawaii and New York have stricter laws regarding the use of pesticides and insecticides.

And, while you may be able to purchase some products from out of state, you’ll be doing it at your own risk. Read labels carefully to find out if the ant killer you want is prohibited in your area. Manufacturers are required by law to list the states their products are or aren’t allowed in.

Protect Your Furniture and Wood Piles from Further Infestations

If you’ve dealt with various insect infestations in the past, you probably know that using repellents is a great way of preventing more pests from moving in. But, treating the problem always starts with a good insect killer and an efficient dispersal system.

The products in this article can handle carpenter ants like a charm. I’ve carefully selected ant killers that you can use in a wide range of scenarios. Pick the best solution for your home and deal with the wood burrowers before they can cause serious damage.

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