Carpenter ants play an important role in the ecosystem, particularly in the breakdown of decaying trees. However, they can also invade homes and other buildings, making nests in damp areas and rotting wood, causing significant damage to the structure. Being able to identify and distinguish carpenter ants from other insects is crucial for determining their presence. You can observe physical traits and signs of infestation to identify carpenter ants.
Steps
Recognizing Physical Features

Look at the color. Carpenter ants are typically brown or black, with some having a combination of black and orange. While color is not the only factor to identify carpenter ants, it is the first feature you can observe.

Pay attention to size. When observing carpenter ants, try to estimate their size. Carpenter ants are not very large. Typically, you will see these ants crawling around inside the house. They usually measure about 1 – 1.3 cm in length.
- However, in some regions, carpenter ants may be smaller. For example, in Minnesota, some carpenter ants are only about 0.5 cm long. When estimating the size of carpenter ants, observe other features as well.

Examine the rounded thorax. The thorax is the body part directly beneath the head of the ant. Carpenter ants have a rounded thorax. The surface on top of the thorax is evenly rounded from head to tail.

Look at the antennae and waist. The middle body segment of carpenter ants is narrow. Their antennae are slightly curved.
- The shape of the antennae and waist helps differentiate carpenter ants from termites. Termites have straight antennae and a broader waist.
Observe signs of infestation

Look for piles of sawdust. Carpenter ants don’t consume wood, but they do burrow through it. They will tunnel into wooden furniture in the house, such as tables or cabinets. If your home is infested with carpenter ants, you may find piles of sawdust beneath furniture like tables and chairs.

Listen for the sound of ants in the walls. Gently tap on the walls inside your home and press your ear to the surface. The tapping usually disrupts the ant colony. If your home is infested, you may hear a faint rustling sound.
- While carpenter ants can nest anywhere in the house, they prefer areas near windows or water sources. It’s not uncommon to find them in the kitchen or bathroom. Try tapping in these areas to locate their nest.

Check for ants at night or early morning. Carpenter ants are typically active after dark, so search for them in places where you hear rustling sounds in the early morning or evening. Use a flashlight to spot carpenter ants in those areas.
Dealing with an infestation

Try using traps. For a minor carpenter ant infestation, you can manage it at home with ant traps. These can be purchased at household stores and placed where you notice ants crawling.
- This method works best if the ants are present outside the house, such as in the hallway. The traps will help prevent ants from entering your home.
- Make sure to read the labels on the ant traps. Place them out of reach of children and pets.

Use insecticide sprays. Insecticide sprays can help prevent carpenter ants from entering your home. You can buy products designed to repel or eliminate carpenter ants at home improvement stores. These are typically sprayed around the house.
- Remember to read the product label for safe use. Most sprays should be kept out of reach of children and pets.

Contact a professional service. If traps and insecticides haven’t resolved the carpenter ant problem in your home, it might be time to reach out to a pest control expert. They can pinpoint the nest and use effective methods to handle the infestation.
- While most professional services use chemicals and pesticides, if you prefer to avoid chemicals, you can discuss natural treatment options with them.
