We have several species of wood destroying ants in the Pacific Northwest. Many species of these ants are native to North America and are most likely to invade the structural wood of homes. Worker ants of the genus Camponotus are identified by the single, large node and the evenly rounded profile of the top of the thorax, and the antennae have 12 segments. Colors range from tan to black to reddish to orange to black/red combinations. Workers vary from 6 to 13 mm in length.
The queen usually likes to make the main colony under a log or stump. After the colony is about 3 yrs old the queen will send her workers out to establish “satellite” colonies for the purpose of raising the reproductives. Wood and the conditions found in homes make an ideal place for these satellite colonies. Trails link the colonies together and the workers bring the reproductive larva to the satellite colony. The milling that these worker ants do can cause structual damage to the house. After 6 months they pupate as reproductives, mate and fly away to start more colonies. Colonies typically are around 15,000 plus workers when mature and can reach over 100,000 under the right conditions. Carpenter ants are polymorphic, with many sizes of workers in the colony.
When the ants mill in the wood they eject “frass”, which is wood chips and other debris that looks like saw dust but is more fine and filled with ant parts. Seeing this frass can let you know that your house may have a carpenter ant invasion.
Try to eliminate conducive conditions for Carpenter Ants. Do not use railroad ties or leave old stump for ant to use as their new home. Cut back all tree limbs and bushes from touching the structure that could aid the ants in finding convenient access they can use to trail into your house.