1.800.858.7378 npic@ace.orst.edu
We're open from 8:00AM to 12:00PM Pacific Time, Mon-Fri

Carpenter Ants

Carpenter ants get their name from the fact that they chew through wood to make nests. However, they do not eat wood like termites. They eat sweet foods, pet food, and other insects. Carpenter ants are commonly found in wooded areas, nesting in trees, logs, and stumps. Carpenter ants may also be found in man-made structures, including wooden doors, ceiling beams, floor joists, under bathtubs, and attic eaves.

Homeowners commonly mistake winged carpenter ants for termites. However, it is very easy to tell the difference. Carpenter ants have sharply bent (elbowed) antennae while termites' antennae are straight. There is also a difference between the types of damage they cause to wood. Carpenter ants produce sawdust as a result of their chewing activities while termites produce little pellets. Contact your local Cooperative Extension Service for more information on carpenter ants in your area.

Control tips:

  • The key to control is finding the nest or nests. Look for piles of sawdust or carpenter ant trails at night when they are most active.
  • Carpenter ants prefer damp wood over dry wood. Increase ventilation in areas like attics, basements, and crawl spaces to reduce moisture.
  • Repair all leaks in the roof, attic, inside the home, and the foundation.
  • Seal areas where plumbing, cable, or electrical hardware enters the home.
  • Consider increasing ventilation or insulating pipes if condensation is a constant source of moisture near wood.
  • Replace water damaged wood, and store firewood several feet away from structures.
  • Keep tree limbs trimmed away from wood structures so that the ants cannot use the limb as a bridge to the structure.
  • Consider reading about how to use Integrated Pest Management (IPM) to prevent and control carpenter ants in and around your home.
  • If a pesticide will be used, always read and follow the label directions carefully.

If you have questions about this, or any pesticide-related topic, please call NPIC at 1-800-858-7378 (8:00am - 12:00pm PST), or email us at npic@ace.orst.edu.

Last updated January 27, 2017

Carpenter Ants

  • Identify the ant species before choosing a treatment strategy. Control techniques may be different for fire ants and other ants.
  • Finding the nest is the key to eliminating carpenter ants.
  • Follow ant trails to find the nest. Carpenter ants use permanent trails
  • Find and repair any leaks that allow wood to get wet. Carpenter ants live in wet wood.
  • Insulate pipes if water droplets form on the outside.
  • Replace water damaged wood.
  • Keep rain gutters clean and drain water away from buildings.
  • Seal any gaps where plumbing, cable, and electrical hardware enters the home.
  • Store firewood several feet away from buildings and off of the ground.
  • Keep trees and shrubs trimmed away from buildings, which may allow ants access.
  • Remove stumps and dead trees, which may harbor a nest.
  • If you choose to use a pesticide, read the label before you buy. Try a lower toxicity product first.

If you have a pesticide product in mind, have your label handy and click here for information about that product.

County Extension Offices

Through its county agents, the Cooperative Extension Service gives individuals access to the resources at land-grant universities across the nation. These universities are centers for research in many subjects, including entomology (the study of insects) and agriculture. Each county within the United States has an Extension office, which is staffed with agents who work closely with university-based Extension specialists to deliver answers to your questions about gardening, agriculture, and pest control. You can find the phone number for your local county extension office in the local government section (often marked with blue pages) of your telephone directory or by clicking on the map below.

Alaska Washington Oregon California Idaho Nevada Montana Wyoming Utah Hawaii Arizona Colorado New Mexico Texas Oklahoma Kansas Nebraska South Dakota North Dakota Puerto Rico Minnesota Iowa Missouri Arkansas Louisiana Mississippi Tennessee North Carolina Alabama Georgia South Carolina Florida American Samoa Guam N. Mariana Islands US Virgin Islands Wisconsin Illinois Michigan Indiana Kentucky Ohio West Virginia Pennsylvania Virginia Washington D.C. Maryland Delaware New Jersey Conneticut Rhode Island Massechusetts Massachusetts Connecticut New York New Jersey Maryland Washington DC Delaware Vermont New Hampshire Maine Vermont New Hampshire
Small Map of US States

U.S. States:

AK | AL | AR | AZ | CA | CO | CT | DE | FL | GA | HI | IA | ID | IL | IN | KS | KY | LA | MA | MD | ME | MI | MN | MO | MS | MT | NC | ND | NE | NH | NJ | NM | NV | NY | OH | OK | OR | PA | RI | SC | SD | TN | TX | UT | VA | VT | WA | WI | WV | WY | Washington D.C. |

U.S. Territories:

Puerto Rico | American Samoa | Guam | Northern Mariana Islands | Virgin Islands

Additional Resources:

Related Topics:

What are pests?

Learn about a pest

Identify a pest

Control a pest

Integrated Pest Management

What are pesticides?

Herbicides

Disinfectants

Fungicides

Insecticides

Natural and Biological Pesticides

Repellents

Rodenticides

Other types of pesticides

Disponible en español

Facebook Twitter Youtube