Carpenter ants (Camponotus)
Carpenter ants are the #1 wood-destroying pest in the Pacific Northwest. Left unchecked, Carpenter ant colonies will cause significant damage to sound wood, possibly compromising the structural integrity of a building.
Carpenter ants are fairly easy for an untrained person to identify with the naked eye based on size and color. The most common local species (Camponotus modoc), is “the big black ant”. Although workers vary in size within a colony, even the smallest workers are larger than most other local ants. Insects have three body segments; and, in C. modoc all three, the head, thorax, and abdomen are black. The abdomen may have some silvery bands. The legs are reddish. The second most common species (Camponotus vicinus) has a black head and abdomen while the thorax has a lighter, usually reddish color.
Carpenter Ant Colony
Before attempting to deal with Carpenter ants, it’s important to know that there are two types of colonies – parent and satellite. A parent colony contains the queen, eggs, and early stage larvae. It is nearly always located outside the structure.
Satellite colonies are established by worker ants. They find an appropriate place above grade (a hollow tree, a post – or a house), prepare the area (possibly by digging tunnels and chambers in good wood), and then carry larvae into the area. The larvae then pupate, and new workers emerge.
A Carpenter ant colony in a structure, in nearly all cases, will be a satellite colony. Therefore, after it has been eliminated, it is essential to keep up a barrier treatment with an effective insecticide. If not treated, primary colonies will simply restock the area with new workers who will continue to damage the wood. Finding primary colonies can be very difficult, since Carpenter ants often forage hundreds of feet from the parent colony. Finding one primary colony does not necessarily protect your structure since there may be another primary colony within range of your building.
How to Get Rid of Carpenter Ants
There are many products and methods to control Carpenter ants. Choosing the best depends on the time of year, location of the nest and many other factors. When Carpenter ants are seen repeatedly inside a structure they are probably from a satellite colony and it is best to contact an experienced Pest Management Professional (PMP).
After leaving the nest, the winged female Carpenter ant will mate and seal herself inside a nest to lay eggs and rear the first generation of workers. The queen will lay a small number of eggs the first year and up to 30 eggs the second year. It takes about 60 days on average for an egg to become an adult worker ant. Worker ants can live up to seven years, while a queen may live up to 25 years. It usually takes several years for a colony to become large enough to produce the reproductive flying males and females.
Tips for Prevention
- Remove any piles of debris, wood, and junk from around your home
- Keep trees, shrubs, and plants trimmed and away from your home
- Caulk cracks and crevices around foundations that provide entry from outside
- Provide a dry, vegetation-free border, such as gravel or stones, around the perimeter of house foundations to discourage nest building. Wood chip mulches and landscape plants provide a good nesting environment
- Keep food put away and don’t leave dirty dishes out