How to Identify and Kill Carpenter Ants

Carpenter ants play a key role in the ecosystem, particularly by helping trees to rot. However, they can also infiltrate houses and other buildings, nesting in moist places, rotting the wood and causing significant structural damage.

Carpenter Ants
How to Identify and Kill Carpenter Ants

Would you like to know how to identify carpenter ants? Identifying and correctly distinguishing carpenter ants from other species is an important factor in determining the appropriate course of action in the control of infestations.

In this Meepo’s guide, you’ll learn “how to tell if you have carpenter ants”:

About the carpenter ants

These insects belong to the genus Camponotus, which includes more than 1,000 species. They live on all continents except in Antarctica. They differ in many subspecies with different characteristics.

About the carpenter ants
About the carpenter ants

However, some traits are common to the whole genus and it is worthwhile knowing them to understand if the ants that are invading your home are carpenters or not. Some common features that you should observe are:

  • Color: usually black, red or intermediate shades.
  • Shape: a segmented body with an oval abdomen and a thin, square thorax. In addition, the upper part of the thorax of the carpenter ants has a smooth and uniform curve and not jagged and irregular.
  • Dimensions: 9-13 mm, depending on the role that the ant plays in the colony.
  • Antennas: yes.
  • Wings: worker ants do not usually have wings. However, relatively rare male specimens may have them.

Where carpenter ants live

They can establish their nest inside or outside of any type of structure. But wooden houses are particularly at risk because these insects love to dig thin tunnels in the wood.

However, unlike termites, ants do not eat wood but simply nest. Because damp wood is easier to excavate than dried wood, the interiors that run the greatest risk of infestation are those near water sources, such as the bathroom and the sink area in the kitchen.

Sometimes, the ants build a network of one or more satellite or twin colonies outside the structure and move between them and their point of support inside, thanks to small cracks and openings.

Where carpenter ants live
Where carpenter ants live

In this case, the outer colonies are often found in old tree trunks, lumber, woodpiles or other areas where damp wood is present. You can often find files of specimens moving from one colony to another in the morning or late afternoon when they are looking for food.

When the ants dig the tunnels, they leave as “residues” a substance that looks like thin sawdust or small wood chips. This substance also contains dead insects. This is an unequivocal indication of the position of the nest. If you meet a small pile of sawdust at home or outside near the house, carefully check the wood you find nearby looking for a tunnel. Probe the wood with a thin screwdriver to identify empty areas inside.

Where to look for active ants

Although they build the nest in the wood, if the carpenter ants decided to colonize the cavity of a wall of your house, you will have many difficulties to find them. If you suspect an infestation, it is a good idea to look for insects in an accessible area where you are quite sure to find them. Some areas of the house are more prone to infestation and accommodate the activity of the ants than others, especially if these areas are wet or give access to food. Here’s where to look for carpenter ants:

  1. Under the carpets: check around the doors, the fireplace and other areas where there is access to the outside.
  2. The patio and the foundations.
  3. Areas with high vegetation. Ants love to nest and search for food forming long lines hidden by all kinds of vegetation. The old tree stumps, the branches resting on the foundations of the house, the patio and similar areas are excellent shelters for these insects. Move the vegetation and look for the ants. When you find a row of specimens looking for food, follow it back to the colony.
  4. The layers of mulch and leaves offer shelter to numerous types of ants and not just to carpenters. You can find the fire ones, the common ones, and the Argentinean ones. Rake the mulch from the ground to find the colonies.
  5. Floors: the plants in the pots, the organic waste bin and any other object that comes into contact with the ground can potentially contain carpenter ants.

Steps to identifying carpenter ants

Meanwhile, if you want to learn further the steps on how to identify and kill carpenter ants, read on and follow this guide.

What you’ll need

  • Magnifying glass

Step by step instructions

  1. Look for wood chips near the cracks in the moldings or siding. Carpenter ants do not eat wood, as is generally thought. They make tunnels and galleries, and take the rest of the material out of the nest by piling it into a cone shape. The remains resemble the shavings of the pencils.
  2. Look for walking carpenter ants at night. Unlike termites, carpenter ants are often seen outdoors, in search of food and water.
  3. By using a stethoscope or magnifying glass, you can hear the carpenter ants poking.
  4. Look for black or red ants. Some carpenter ants have both colors. A common species in California (Clarithorax Camponotus) is yellow and black.
  5. Measure them on paper with a ruler. If you can not do this, do your best to estimate its size. Carpenter ants vary in size according to their function in the colony and its genus. However, they are generally larger than any of the many varieties of common ants in houses. Among the most common species of black carpenter ants in North America, is the Campontonus Pennsylvania, which has a size of 5/16 inches (0.8 cm) to 1 inch (2.54 cm).

They are measured thus:

  • The queen ant: the queen is the largest of the ants in the colony, and can be as long as 1 inch (2.54 cm).
  • Princesses and Drones, females and males: 3/4 of an inch (1.9 cm).
  • Older workers: Among the black carpenter ants, their range goes from 3/8 to 1/2 inches (1 cm to 1.3 cm).
  • Minor workers: from 5/16 to 7/16 inches (0.8 cm to 1.1 cm.
  1. Look for a distinctive heart-shaped head with large jaws and angled antennae.
  2. Look for a single segmented pedicle or waist constricted between the thorax and the abdomen. Other ants may have 1 or 2 nodes in the waist. Winged carpenter ants are sometimes confused with winged termites but are easily distinguished by examination of the pedicle. Termites have a broad, segmented waist that tapers towards the abdomen.
  3. Look for a soft, rounded upper thorax. Fire ants and common garden ants have a rigid chest.
  4. Search and check that the wings in front are longer than the wings on the back.

How to Kill the Carpenter Ants

Carpenter ants are very common, but also extremely destructive. Without control, they can quickly infest an entire structure. For this reason, it is important to identify and exterminate them as soon as you notice them, to avoid serious structural damage that is very expensive to repair.

How to Kill the Carpenter Ants
How to Kill the Carpenter Ants

Continue reading this tutorial to free yourself from an infestation of carpenter ants.

Part 1: How to kill carpenter ants

What you’ll need

  1. Gloves and long-sleeved clothing
  2. Vacuum cleaner
  3. Insecticides


Be very careful when trying to manage these insects. Although accidents are rare, it is worth mentioning this warning: never handle the ants or their nest directly. Although these insects are not particularly aggressive and likely to bite humans, they can react and inflict very painful bites if annoyed or in danger. Carpenter ants are known for spraying formic acid into the bite wound, so if you want to avoid unnecessary pain, do not touch them and do not handle their nest if it is not strictly necessary. Ensure you wear gloves and long-sleeved clothes.

Step by step instructions

  1. Locate the colony or colonies. The first step in eliminating these insects is to find the nest. Look for the ants themselves, small holes or piles of sawdust as described in the first section of this article. Pay particular attention to all areas where damp wood is found. You can make sure that the wood is not infested even by tapping it on the surface. The pieces of wood that contain many ants are thin and hollow compared to the intact ones. Drumming the wood disturbs the ants and force them out of the nest, so you will see them better.

Remember that very large nests often have satellite colonies located nearby and you need to identify them if you want to eradicate the infestation.

  1. Destroy or remove the colony. If it is a small nest or one with easy access, it is sometimes possible to get rid of it easily. If the colony is outside the house, carefully throw the infested wood using impenetrable material like a plastic sheet. This way, you will protect yourself while you manipulate the nest.

However, in case the colony is at home, some websites of disinfestation companies recommend using a vacuum cleaner with a hose accessory to suck up all the insects. If you opt for this solution, remember to seal and throw the household appliance bag in the trash, to prevent any surviving insect from escaping.

When you find a colony that has dug many tunnels in the wood of the house wall, do not remove the piece of the wall because you could compromise the structural integrity of the house. In this case, call a professional.

  1. Use lures to handle the colonies that you cannot handle directly. Sometimes, you may not be able to find the nest. However, if you find a significant number of insects, you can put insecticide substances along their pathways to control or eliminate their population. Many baits, traps, and insecticides are available for free sale to the public. Contact a gardening store to find the solution that best suits your needs.


Be very careful when you decide to use poisonous baits at home, especially if you have young children. Make sure they know it’s not something edible or, if they’re too small to understand, always check them out.

  1. Contact a professional. If you are not able to find and eliminate the colony quickly and the insecticides have not given the desired results, then the best solution is to contact a company specialized in insect disinfestation. These people can buy insecticides and other tools that are forbidden to the public and, more importantly. They have the knowledge and experience necessary to find and manage the colony of carpenter ants in an intelligent and effective way, much more than ordinary people can do.

Remember that some disinfestations may force you and your family to leave the house temporarily for a day or two.

Do not delay and call a professional. The more you spent time dealing with the infestation to no avail, the bigger the colony will become that will create extensive damage to your property.

Part 2: Preventing infestations of carpenter ants

What you’ll need

  1. Silicone or stucco resistant
  2. Eliminate any source of moisture. Water is a determining factor when it comes to carpenter ants infestations. Often a piece of wood becomes susceptible to hosting these insects after it has been exposed to moisture. Repair or seal any water loss at home to prevent ants from nesting in your home.

Below are some suggestions to eliminate moisture that helps to attract insects:

  • Check that window frames have no cracks.
  • Check that the roof and walls that are most exposed to the weather do not have cracks.
  • Make sure that the attic, the basement, and the narrow spaces are always well ventilated.
  • Search and repair leaky pipes.
  • Clean the obstructed gutters and eliminate water leaks.
  1. Seal entry points, cracks, and crevices. If carpenter ants are not able to get in and out of your house, all internal satellite colonies will be isolated and the ants will die. Check the outside of the house for cracks, holes or other small openings that can become a passage for the ants. Pay particular attention to the areas around the outer walls, near the ground and the foundations. Seal all the holes with silicone or with a stucco resistant. Also, check the areas where the water and electrical systems come into the house since they are vulnerable points also.
  2. Eliminate all wood residues that are close to home. Since these ants love to nest in the wood both at home and outdoors, it is vital to find and rid all the infested wooden blocks to prevent the insects from moving into your home. Check all the areas where wood is present; if you find signs of the presence of carpenter ants, remove the timber. Here’s where to look:
  • Old tree stumps.
  • Wood stacks.
  • Old trees, especially those with branches that touch the house.
  • Piles of garden waste.
  1. Install artificial barriers. If carpenter ants are a recurring problem, then you should create a strip of pebbles or gravel all around the house. This “barrier” is rather inhospitable for the ants and could discourage them from approaching the house and then enter through cracks in the foundations. Consult with a building contractor to understand the feasibility and costs of these works. On the other hand, if you are particularly adept at gardening, you can get involved in this project to protect your home.

Tips and warnings

  • Use both liquid and solid bait for exteriors when possible. Carpenter ants feed on aphids, so giving them something that looks like sweet honey from aphids will drive them crazy and help you control their population.
  • This species of insects are very active at night. Get a flashlight and go outside. Look for ants on trees, wood, and other places where they could have nested. You can also follow the columns of specimens from the structure that have infested up to the nest.
  • Do not use spray or powder pesticides of any kind when using bait because they contaminate the bait.

You may also find this homemade method of killing carpenter ants useful:

How to get rid of carpenter ants in walls

The existence of large black ants sometimes implies that your house is attacked by carpenter ants. If that’s the case, you don’t want that because if you don’t notice them on time, they can eat through areas of your house.

How to get rid of carpenter ants in walls
How to get rid of carpenter ants in walls

People sometimes suppose that every big black ant is a carpenter ant that can bring instant panic; however, not all big black ants are carpenter ants. To correctly recognize them, all you need to understand is a little fundamental biology. Since carpenter ants can cause important structural damage, you need to understand how to acknowledge them relative to other ants species.

When a carpenter ant nest is positioned in a wall cavity, you will need to open the wall before implementing a foam or dust item. There are two methods to open a wall for getting rid of carpenter ants in walls.

The first method is to remove parts of sheetrock.

The second method is the drill hole through the sheetrock.

Holes should be 1⁄8 “inch long and span 2 to 6 feet on either side of the entrance of the insects

This will maximize your opportunities of getting in touch the nest and the queen immediately

For small areas, choose a fit-to-use foam item that comes with a small flexible pipe and nozzle for fast and simple implementation

For large areas, a foaming agent and foaming machine are required to apply the foam inside the wall

Non-repellent foams handle more slowly than dust however give the advantage of extending in the room to cover a bigger zone.

An extra advantage of non-repellent foams is how the active ingredient is distributed into social interaction to prevent the entire colony

For dust treatments, ensure to choose an item marked for carpenter ant control. You should have a hand duster to handle the dust.

Insert the tip of the filled duster into the drilled holes and apply evenly. Dust will lead the ants to die sooner than with foam, but you might have to drill more holes or open the door more than that to ensure you get even protection.

And it’s that easy with the expert help how to get rid of carpenter ants in walls.

We hope this tutorial will be of help to you. Do share your opinion on the article in the comment section. Don’t forget to like and share the article. Sharing is caring!

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