A common destructive insect pest

1. Modoc : all black. (Legs may have a rusty red color) One queen in parent nest.

2. Vicinus : black head, rusty red thorax (mid section) and black abdomen 
(tail section.)  Multiple queens in parent nest.
Most carpenter ant species have other similar characteristics. See digital photos.

Five Sizes : Carpenter ants can be as small as one quarter inch or as large as three quarters of an inch. All sizes can be found in one nest. (See illustration above)

Most Carpenter Ant species establish their initial nest in decayed wood, but, once established, the ants extend their tunneling into sound wood and can do considerable damage to a structure.
These species commonly nest in standing trees (living or dead), in stumps, or in logs on the forest floor. Since many houses are being built in forested areas, well established, vigorous colonies are readily available in the immediate vicinity to attack these dwellings. This is especially true when the homeowner insists that the home be built with a minimal removal of trees.

Carpenter Ants typically have a parent colony in outside nesting areas, such as live or dead trees, stumps, logs or decorative landscape wood. When the colony grows larger and needs room to expand satellite colonies are established. These satellite colonies often develop in nearby structures presumably because they offer warm protection.

Only the parent colony contains the queen(s), young larvae and workers, while the satellite contains the mature larvae, pupae, workers, and/or winged reproductives.  Ants move back and forth from parent nest to satellite nest but just a few ( less than 10 % ) will be visible foraging for food.

Sometimes they can be seen moving mature larvae (white and grub-like) or pupae (papery cocoons).

Ants are generally active along ant trails from April to mid-October. These trails follow natural contours and lines of least resistance and also frequently cut across lawns. Traffic on these trails may be noticeable during the day, but peak traffic occurs after sunset and continues throughout the night.

The parent colony is often located in a tree, stump,  stacked wood within 100 meters of the house or wood and stumps buried in the yard when the house was constructed. Decorative wood  landscape ties brought in to enhance the beauty of a yard or driveway may also be the source of a parent colony. The colony does not produce reproductives (winged males and queens) until it is from 3 to 6 years old and contains about 2,000 workers. The natural food for these ants consists of insects and other arthropods and sweet exudates from aphids and insects. They are also attracted to other sweet material such as decaying fruits.

Reproductive carpenter ants ( winged males and females ) leave the nest as early as January if the nest is in a heated structure. Those living outside in logs and stumps will not swarm until about early May. The fertilized queens must then find wet wood to establish a new nest, and the cycle starts over again.  See digital photos.

The new queen could live 15 years or more and lay 70,000 fertilized eggs.