Description: Carpenter ants are among the largest ants in the north central states. They are black, or red and black; workers range in size from 3/16 to 1/2 inch. Colonies consist of major and minor workers. Carpenter ants have the following characteristics: 1) petiole with one node and 2) a thorax with an evenly rounded upper surface (workers only) [compare with field ants].

Foods: Other insects, both living and dead. They also feed on meats or sweets, including honeydew, syrup, honey, sugar, jelly, grease, and fat. Carpenter ants do not eat wood; they chew wood into sawdust in the process of creating galleries and tunnels.

Nesting Sites: All types of moist or rotting wood, including trees or tree stumps, indoors behind bathroom tiles; around tubs, sinks, showers, and dishwashers; under roofing, in attic beams, and under subfloor insulation; and in hollow spaces such as doors, curtain rods, and wall voids. Carpenter ant tunnels are clean and look very smooth, making the wood appear that it has been sandpapered. In contrast, termite tunnels are not clean looking, but are packed with dirt-like material.

Mating Swarms: April through June. Occasionally swarms may come out earlier during late winter on warm, sunny days.

Best Pest Management Methods: The best control is to apply an insecticide directly into the nest. It is also important to replace damaged or decayed wood, and if possible to eliminate any moisture problems.