Carpenter ant workers vary greatly in size (and sometimes color!) , measuring 1/8 to 1/2 inch long. Queen ants measure 1/2 to 3/4 inch long. Depending on the species, these ants may be totally black, combinations of red, orange, yellow and black, or completely red or brown. The thorax profile is evenly rounded on the upper side. The waist (pedicel) is 1- segmented (one node). Carpenter ants do not have a sting. However, larger species can inflict a painful pinch using their jaws (mandibles); grasped workers are capable of emitting a strong formic acid odor.
The most common structure-infesting carpenter ant species in Illinois is Black carpenter ants (Camponotus pennsylvanicus), which have workers that measure 1/4 -1/2 inch long; they are completely black except for fine pale yellow “hairs” on top of the gaster (plump part of the abdomen). The queens can reach 3/4 inch in length. This species is common in both rural and urban settings and is responsible for most of the carpenter ant-related damage to structures in Illinois.
Black carpenter ant colonies are of moderate size, usually containing over 3,000 workers (up to 15,000, including satellite nests) when maturity is reached in about 3 to 6 years. Developmental time (egg to adult) for workers takes at least 60 days. Workers are of different sizes (polymorphic) with majors, minors and intermediates present. There is usually only one functional queen per colony. Once established, she chews off her wings and remains wingless for the duration of her life. Swarmers are not produced until the colony is usually 3 ½ to 4 years old. Swarmers appear from May until August.
The only external indication of infestation other than the presence of workers and / or swarmers (winged queens and males) is the appearance of small openings or windows on the surface of wood. Through these, the workers expel debris, which consist of sawdust-like shavings, fragments of insulation and insect body parts . The accumulation of such debris (frass) below such holes is a good indication of an infestation.
Inside, the galleries follow the softer spring wood with numerous connections through the harder/dark summer wood. The gallery walls are smooth, with a sand-papered appearance. The active galleries are kept clean of debris. These ants prefer to attack wood softened by moisture and fungal rot; therefore, they are often associated with long-term moisture problems in structures.
The presence of a carpenter ant nest is sometimes indicated by a rustling sound coming from wall voids or from wood where the colony is located. Otherwise, the emergence of swarmers indoors may be the first indication of an indoor colony. The workers forage for distances of up to 300 feet from the nest. They typically enter buildings around door and window frames, eaves, plumbing and utility line penetrations, and shrub and tree branches in contact with the building.
Although some workers are active during the day, most activity is from dusk till dawn, with peak activity between 10 pm and 2 am.
Carpenter ants feed primarily on insect honeydew, plant and fruit juices, insects, and other arthropods. Inside, they will also feed on sweets, eggs, meats, cakes, and grease.
What you can do: All branches of trees and shrubs in contact with the building must be trimmed back. One should check where electrical and water lines enter the building and caulk any gaps.
Store firewood away from your house, trim dead limbs from trees, and remove stumps and lumber from around the house. A frequently overlooked ant control measure is to make sure that all plumbing or roof leaks are sealed.
On warm evenings, a night-time inspection of the ground and outside walls around the residence will reveal carpenter ant trails activity sources, and entry points. These observations should be reported to your Quik-Kill technician in order to speed the process of colony location.
We use a three step approach:
1) The first step for the Quik-Kill pest management professional is to determine if the ants present are merely foraging inside or if there is one or more nests inside. The best indication of a nest is the presence of sawdust piles containing insect body parts. Another indication is the sound produced as the workers remove wood to expand the nest. Outside, the technician will check around the building’s perimeter for foraging trails, especially in the direction of trees and shrubs. [Trails are easiest to locate between sunset and sunrise when the ants are most active; therefore; the property-owner’s overnight observations would prove valuable to the attending technician.]
2) The second step is to locate any inside nest(s). Carpenter ants have a network of trails they follow throughout a structure and often use edge lines, the tops of electrical wires and water pipes. These features will be examined by the technician.
3) The technician will determine if the inside colony is a parent or satellite colony. This is accomplished through Inspection and observation of activity. Detection of a trail will direct the technician to the parent colony. If the colony or colonies are located, the technician will appropriately treat them . Inside, this may involve drilling wall voids and injecting materials or drilling wood members and injecting them. Exterior perimeter barrier treatments are effective in preventing carpenter ant entry. If your circumstance warrant it, we sometimes treat (banding) the bottom 3 to 6 feet of tree trunks and/or utility poles.