How to Get Rid of Carpenter Ants

Anytime you face a pest infestation, it’s a stressful situation. But when you have pests that can damage your property, that’s a whole new level of stress. Carpenter ants chew through wood in homes and yards across the country. Thankfully, we’ve got some advice on how to get rid of carpenter ants indoors and outdoors. 

In this article we’ll cover:

• What are Carpenter Ants?
• How to Get Rid of Carpenter Ants Indoors
• How to Get Rid of Carpenter Ants Outdoors
• How To Prevent Carpenter Ants From Returning
• What Causes A Carpenter Ant Infestation?
• Signs of a Carpenter Ant Infestation
• FAQ About Carpenter Ants

What Are Carpenter Ants?

Carpenter ants (Camponotus) make their homes in trees and logs, easily chewing through wet wood to create their tunnels and nests. These ants come in different sizes and colors, but in North America, they mostly appear black or reddish brown.

Carpenter ants are typically between one-quarter inch and five-eighths of an inch in length, with elbowed antennae. Some carpenter ants may develop wings while the nest is swarming.

How to Get Rid of Carpenter Ants Indoors

Like most ants, carpenter ants give each other directions to food and shelter by leaving behind a pheromone trail. It’s how they sneak into your kitchen or bathroom in vast numbers. 

Thankfully, we have some helpful tips for controlling carpenter ants in the home. Infestation sizes may vary, but following these steps in the suggested order mimics professional treatments and can save you the cost of hiring an exterminator.

Step 1: Locate the Nest

The first step to ending your carpenter ant problem is to locate the nest. Follow the ant trail or evidence of damage until you reach the nest. 

Sometimes these nests are difficult to find. Try thumping the wood where you suspect damage. If it sounds hollow, you’re in the right place. Thumping around the nest can excite the ants, and panicked ants may appear. 

Step 2: Set Baits

Once you find the nest (or locate high ant activity) apply bait traps or bait gel nearby. Spread your bait around sinks, appliances, baseboards, and bathroom fixtures. The nest is usually near a source of water. Consider using a duster for a quick and even application of fine granular baits. 

Baits eliminate ants by lacing their food with insecticide. When the ant takes the bait back to share it with the colony, that insecticide spreads amongst the other ants until it dethrones the queen. 

Step 3: Apply Aerosol Foam

Next, apply an aerosol foam to cracks, holes, and crevices. Insecticidal foams expand, making them the ideal choice for wall voids, cracks, and crevices.

Aerosol foams like FiPro spread pesticides from ant to ant, infecting the entire colony. When ants come in contact with these foams, their nervous systems are affected, resulting in death. 

You can use insecticidal dust to pump pesticides into hard-to-reach places like behind sinks and inside hollow doors. 

Step 4: Sprinkle Diatomaceous Earth

Another option is to use diatomaceous earth (D.E.) to solve your carpenter ant problem. Just sprinkle this pesticide along the pheromone trail or near suspected entry points to your home. 

Diatomaceous earth eradicates pests dehydrating their bodies. This dehydration occurs either by consumption or the proximity to D.E.

You can use boric acid in the same manner. Boric acid takes longer to kill insects than D.E., but both are effective means of carpenter ant control. Diatomaceous earth can be used outdoors as well.

How to Get Rid of Carpenter Ants Outdoors

Are carpenter ants infesting the wood frame around your compost pile or chewing away at your wood deck? Similar to indoor infestations, you’ll need to find the nest and treat it with pesticides. 

Step 1: Spray Outside

Perimeter treatments are advisable whether your infestation is indoors or outside. Use a non-repellent insecticide to spray wall voids, crevices, windows, eaves, and potential entry points. This will help ensure the outside infestation doesn’t migrate indoors. 

Spray the insecticides in a sweeping motion 1 to 3 feet up the wall and 1 to 3 feet into the yard to create a strong barrier around your home. 

Always read and follow the instructions listed on the product label, as guidelines may vary from product to product. 

Step 2: Disrupt Pheromone Trails

Repellents are a helpful tool to rid your lawn of carpenter ants. Carpenter ants are sensitive to strong odors, and the odors will disrupt the pheromone trails they use to direct other ants.

Scents like peppermint (oil), lemon, vinegar, and chili powder can keep carpenter ants away. 

Add your chosen repellant to a spray bottle and dilute it with water. Aim for a 1:1 ratio. Spray your natural repellent solution around any potential entrances to your home or in areas where you see carpenter ant activity.

Step 3: Set Baits

Just like you would indoors, scout your yard for signs of carpenter ant activity and set up bait traps. 

Another way to rid your lawn of carpenter ants is with homemade bait. Start by mixing one-thirds sugar with two-thirds boric acid. Next, place your mixture in a small dish or bottle cap near ant trails or the nest.

Boric acid is widely available at grocery stores, pharmacies, and supercenters.

Step 4: Control the Aphid Population

Aphids and carpenter ants have a symbiotic relationship. The aphids create a food source for the ants (honeydew), and in return, the carpenter ants protect the aphids from predators. If your lawn is teeming with aphids, there’s likely a carpenter ant infestation nearby.

Luckily, aphids can be eradicated with pesticides, soapy water, neem oil, or petroleum-based horticultural oils. Once the aphid population is reduced, the ant colony will likely search for a new source of food elsewhere.

How to Prevent Carpenter Ants from Returning

The best way to prevent pests is to remove their food source and tidy your home and yard. 

• Don’t leave food out: The only thing carpenter ants like more than aphid honeydew is your food. Leaving food out offers pests a steady food source. Be sure to put your food away in sealed containers and clean food prep areas after every meal.

• Clean counters: Clean areas with dish soap or a 50/50 solution of white vinegar and water. 

• Remove rotted, infested wood: If your scrap pile is full of wood or the old tree stump is rotting in the yard, it’s time to make adjustments. Wood that becomes too wet cannot dry out, leading to rot, which invites pests.

• Move firewood: Raise firewood off the ground and store it away from the elements. Place a tarp beneath your wood or purchase a wooden log store to secure your firewood.

• Trim tree branches and bushes away from your home: Tree branches and bushes should never touch your home. Branches risk snapping and causing damage to people and your property. Plus, pests use trees and bushes to gain entry into your home.

• Repair leaks: Leaks around faucets and tubs create damp wood that invites pests like carpenter ants. In addition to being a waste of water, leaks around your home will invite pests who are looking for a consistent source of water. 

• Add caulk to window seals and around faucets: By neglecting the seals around your faucets and window sills, you risk moisture leaks and energy waste. Save money and seal out pests and moisture by caulking your windows, cracks, and crevices.

What Causes a Carpenter Ant Infestation?

A carpenter ant infestation can happen anywhere. These ants need damp wood to make a home and a consistent food source.

Common causes of a carpenter ant infestation include: 

• Any food left out (including pet food). Carpenter ants love sugar, jelly, meat and honey.
• Unsealed garbage cans
• Aphids in your yard, carpenter ants feed on the excrement aphids produce, known as honeydew. 
• Sources of excess moisture, such as leaking pipes or dripping faucets. 

Signs of a Carpenter Ant Infestation

A carpenter ant sighting in your home doesn’t necessarily mean you have an infestation. It could just be a worker ant scouting out a new location for a nest. However, if you see winged carpenter ants, that means a colony is swarming and might be trying to move into your area.

Signs of an infestation in your home include:

• Frass: very fine sawdust from burrowing ants 
• Tiny pin-sized holes in your wood
• Hollow-sounding wood
• Large winged ants seen around your home
• A crinkling, rustling sound in your home (especially at night)
• Ant trails in your home or yard
• Shed carpenter ant wings
• Fecal matter with frass

FAQ About Carpenter Ants

How do I know if I have termites or carpenter ants?

Both termites and carpenter ants can damage wood, leaving evidence of frass (wood shavings). Despite looking so similar and causing similar damage, they require significantly different treatment, which is why proper identification is so important. Here are some helpful tips to tell them apart: 

Carpenter Ants	Termites
Carpenter ants are discrete in their nest building, often unbeknownst to homeowners.	Depending on the species, termites typically cause damage out in the open. Termites also construct mud tubes that are often visible outside of the nest.
Carpenter ant bodies are pinched at the neck and waist.	Termite bodies have a similar thickness throughout.
Carpenter ants have six long legs.	Termites have six short legs.
Carpenter ants have elbowed antennae.	Termites have straight antennae.
Carpenter ants have two pairs of wings with the front wings much larger than the back wings. The wings also have fewer veins than termite wings.	Termites have two pairs of wings of equal size with many veins.

How did carpenter ants get into my home?

Carpenter ants likely entered your home through cracks and crevices. They can travel across tree limbs and wires and even chew through wood to enter your home.

Monitor points of entry such as any place wires enter your home. Check your baseboards and window sills, and keep shrubs and tree limbs away from your home.   

How long does it take carpenter ants to destroy wood?

The good news is it can take years for carpenter ants to cause notable damage, unlike termites, whose damage becomes evident in a few months.

When to Call a Pest Control Pro

Pest infestations can be overwhelming, so there’s no shame in hiring a professional exterminator. If your carpenter ant infestation is in a difficult-to-reach location, or pest control isn’t your forte, hire a pro for the job. 

Pests like carpenter ants don’t like a manicured lawn. They prefer tall grass to hide from predators. Connect with a local lawn care professional who can keep your lawn tidy and ward off outdoor pests.

Main Photo Credit: Geoff Gallice / Wikimedia Commons / CC BY 2.0