Carpenter Ants are the most common wood destroyer in the Pacific Northwest. They even surpass termites as a major structural pest in the Pacific Northwest and the Northeastern United States. They are second in these areas only to fungus that causes dry rot.
Carpenter ants are one of the largest ants in the world, they are polymorphic, which means workers vary in size. (1/8 to 3/4 in.) As with all ants, they have pronounced body segments and elbowed antennae, but their antennae have 12 segments. Distinguishing features of the carpenter ant include an evenly rounded thorax (when viewed from the side) and a circlet of hairs surrounding the anal opening.
The most common are the Modoc which are primarily black, then next is Vicinus which have a dark red thorax, others can be black and red, or brown in color.
Carpenter ants form nests in wood by tunneling against the grain. These galleries are free of mud and sawdust. Coarse sawdust is present below the entrance of an active nest.
Carpenter ants keep occupied galleries clean. They push sawdust out small holes in the wood called windows. This often results in a cone-shaped pile accumulating just below the nest entrance hole. This pile may include, in addition to the wood fragments, other debris from the nest, including bits of soil, dead ants, parts of insects and other remnants of other foods they ate.
The diet of carpenter ants is quite varied and includes living and dead insects, honeydew from aphids, sweets, meat, and fats. They do not eat the wood, they just tunnel in it.
Carpenter ants construct their nests in hollow trees, logs, posts, landscaping timbers, and wood used in homes, and other structures. Workers within a colony have different tasks (food collection, brood tending, etc.). The peak activity hours for a colony are midnight, they avoid sunlight because they cannot monitor their temperature. On cold winter days the colony will use the time to enlarge their colony. If it's below freezing, they'll go dormant untill it warms up.
A single queen founds a colony and raises the first brood of workers herself. A colony isn't strong enough to produce new kings and queens for a few years. When a colony has become large enough, the queen will produce winged reproductives. These swarm and mate in late fall or early spring, when the humidity conditions are correct. The newly inseminated queens seek a suitable place to start a new colony. If you see winged reproductives the colony most likely has been there for several years.
Vicinus (black and red) Carpenter Ant colonies are among the largest carpenter ant colonies, composing of as many as 100,000+ workers. This is because vicinus carpenter ant colonies can be polygynous (more than one reproducing queen), the more inseminated queens, the more workers and winged reproductives they can produce.
Other species of Carpenter ants have one primary queen that started the colony and produces winged reproductives as the colony grows. As time goes by, more uninseminated queens can also produce offspring, but these are only workers for the colony. Some of these colonies can have workers that can produce males.
In Carpenter ant colonies, there is usually one "parent" colony where the queens, workers and young larvae reside - usually in a living tree, a stump or fallen log where the wood is fairly moist. Vicinus carpenter ants aren't as picky as some other species, and may set up colonies under rocks or in mulch. As a colony gets larger, satellite colonies are established. These colonies contain workers, larvae, pupae and winged reproductives.
Foraging ants have been seen entering homes along telephone wires or along branches touching the roof or even from ground trails that come under a door. In such cases, the house will most likely contain a satellite nest.
The ants move back and forth from parent nest to satellite nest to feeding areas (in nearby evergreen trees and shrubs such as Douglas fir, true fir and cedar). Sometimes they can be seen carrying mature larvae (white and grub-like) or pupae (papery cocoons). At any one time only a small percentage (1%-3%) of the ants are outside the nest foraging for food and water.
Satellite colonies are often located in wood containing less moisture than the parent colony because drier conditions are more conducive to the development of the maturing larvae and the pupae. If a colony is established in a house, it is usually a satellite colony - structures rarely have high enough humidity to sustain a parent colony. When carpenter ants decide to move in, they can show up with thousands of workers and just start mining away to make a satellite colony. Satellite colonies have been found in wall voids containing more than 100,000 pupae cases. Structures located near the edge of the forest were more liable to attack than those located further away. This is because the ants which have well-established nests in trees or stumps can easily move to the nearby house and establish satellite colonies.
The nest may also make sounds: Rustling or tapping noises produced when disturbed ants rasp the substrate with their mandibles or gasters or when excavating wood. (Other insects such as termites, the golden buprestid, or yellow jackets nesting in wall voids also produce sounds.)
Evidence of Infestation
Presence of ants (workers or winged reproductives): An occasional ant may be a scout looking for food and may indicate the presence of a nest, if continuous or numerous ants are seen a professional inspection is advised.
Look for Sawdust with bug or ant parts in it: Accumulating in piles or caught in spider webbing; has a finely-shredded appearance. Do not confuse with small sawdust from construction.
Ants love to nest in:
- Wood frame structures
- Crawl spaces
- Cedar or plywood siding
- Under the roof shingles, in-between the paper and sheeting
- Vegetation (trees and shrubs) surrounding the house
Carpenter ants will nest in homes of any age, we have seen carpenter ants build a satellite nest in by infesting joists on a brand new home before the dry wall was even put up.
Most common carpenter ant nest locations: Exterior wall voids are the most common, Attics, cathedral Ceilings, and Crawl spaces. Also interior walls, roof, sill plate, and supports in crawl space and they are very common in firewood or stacked lumber.
Nests have been found in: porch pillars, support timbers, window framing and sills, roofs, shingles, siding, girders, joists, studs, casings of houses, garages and other buildings, insulation, drawers of dressers and cabinets, behind books, in hollow doors, under floors, attic spaces, buried wood, stumps or construction debris.
Nest Locations - Outside Structures
Live trees (excavate heartwood; enter by knotholes, wounds, etc.), dead trees, stumps or logs, buried wood, wood debris, decorative wood in landscape, stacked lumber, or firewood.
Number of Colonies
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 or the old nest becomes less suitable, they expand to form satellite colonies. These satellite colonies are placed in nearby structures presumably because the heated, protective structures are more conducive for the older stages.
The parent colony contains the queen, young larvae and workers, while the satellite contains the mature larvae, pupae, workers, and/or winged reproductives.
If the parent nest is not found, it can reestablish satellite colonies after the pesticides have become inactive or establish new colonies in untreated areas of the house.
If several nests are found, it is important to determine if they are from the same colony (therefore one parent nest) or 2 or more different colonies (therefore several parent nests). Place 2 ants, one from each trail or nest, in a jar:
- Ants from the same parent colony coexist peacefully
- Ants from different colonies may fight
Ants move along definite trails by following a chemical scent or visual clues. These trails can be above ground or subterranean and are actually constructed by cutting away vegetation, removing pebbles, excavating soil and even by covering open trails with a roof of needles from nearby trees. Trails can vary in width from 1/8" to 3/8".
The ants from a colony will follow the same path each year even if grass has grown in it. They will clear the old trail.
Trail Locations Outside Structures
Ants follow natural contours. They will cross lawns and flower beds but often prefer the cover afforded by moving along the edges of things.
- Edge of driveway or sidewalk, mowing strips
- Under patio blocks, wood steps in landscape or wood planks
- Edge of foundation, planters, or sidewalk
- Edge of lawns or flower beds
- Fence stringers
- Excavate along tree roots (easy access to crawl space via roots of trees or stumps which extend under the house)
Trail Locations Inside Structures
Again - ants prefer natural, easy and protected routes:
- Edges of cabinets or furniture
- Excavated trails through insulation in wall voids
- Along wiring or plumbing which cuts through studs
- Wires or branches coming to the house
- Root channels from infested trees or stumps which go beneath the house.
Activity Along Ant Trails
- Ants are generally active along ant trails in western Washington from April to mid-October.
- Hours of greater activity are from 8 p.m. - 4 a.m. although some ants can be found at all hours.
- A sudden increase in activity occurs 5-10 minutes after sunset and is greatest from about 10 p.m. to 2 a.m.
- Temperature or rainfall doesn't seem to influence this activity.
Ants returning to nests are either:
- Larger with full (stretched) stomach so they look somewhat banded
- Carrying food such as insects.
- Some ants will be going to the feeding areas (usually trees). They are not stretched or banded. Some will be engaged in trail building (at night mostly).
Following Ant Trails to Locate a Nest
Do not disturb any trails until you locate the nests. The ants will just get sneaky and reroute the trail which may take much longer to locate.
Ants will generally be going to and from:
- Feeding areas
- Parent nests
- Satellite nests
Banded ants or ants with insects will be going from feeding grounds to parent (or satellite) nests. The young growing larvae and queen need the most food, so more ants will take food toward the parent colony, with fewer moving toward the satellite. Ants carrying larvae or pupae (papery cocoons) are moving from the parent to satellite colony.
Activity is greatest after sunset (roughly between 10 p.m. to 2 a.m.) therefore making it easer in following a trail. A red light disturbs ants less than white light.
Trails may be difficult to locate since they may disappear under boards, sidewalks, or go underground.
You have time! Keep watching for clues as you work in your yard or house. Don't get trigger-happy and spray the trail, or you will have to start over if you want to find the nest.
What Carpenter Ants Eat
Carpenter ants cannot eat solid food. They have a very long, exceptionally thin esophagus (food pipe) that prevents them from eating solid food.
- Mostly they gather aphid honeydew or tree sap.
- Only about 1% of the ants carry insects or insect parts. Insect prey includes grasshoppers, crickets, leafhoppers, aphids, craneflies, mosquitoes, honey bees, moisture ants, thatching ants, spiders, daddy-long-legs and larvae of moths, bees, flies and earthworms.
- Human food includes candy, honey, syrup, soda pop, apples, raisins and pet food.
- The ants have been observed taking "solid" food over to water where it becomes soggy. They can eat the dissolved portions.
- They can masticate ("chew") insect parts and extract nutritious liquids.
Carpenter Ant Life Cycle
Reproductive ants (winged males and females) leave the nest anytime from early January through June (different colonies leaving at different times). Mating takes place in swarms, with the first mating swarms noted in May (others in June, July, August and September).
Mated queens find a suitable place to live and chew off their wings, excavate a smhome and begin laying eggs. Mated queens lay eggs which become workers or queens. Unmated queens or queens which have run out of sperm can produce only males.
By the end of the summer either workers have emerged or the larvae from late eggs and pupae become dormant when the temperature is below freezing.
The dormant phase for the pupae usually ends about mid-January, when the queen begins laying eggs again.
The rate of growth of a colony from one queen in the first year, is very low (with only 1 or 2 dozen workers).
It takes about 3 years to produce even a few larger workers. The number of years it would take to produce reproductives is estimated to be 3-5 years. Therefore parent nests with larger ants or winged reproductives have been in place for a considerable period of time. Satellite nests could have reproductives in a single year because the pupae are carried from the parent nest to the satellite.
- If the queen dies, workers can produce eggs which become males.
- Workers must help the new adults emerge from the pupa case; without workers they can't emerge.
- If the food supply is low it severely stresses the colony and retards its growth. The queen and workers can eat their own eggs and smaller larvae.
Managing Carpenter Ants
Finding both the parent colony in the surrounding landscape and the satellite colony (or colonies) in the structure is crucial to successful control of carpenter ants.
Many pest control operators feel they can drill and inject the entire house faster and at less cost to the homeowner than it would take to locate and treat the nest areas. Others feel they can starve out the ants by spraying only the perimeter (attic, crawl space, and foundations) at monthly intervals for a year.
We recommend careful inspection and professional attempt be made to penetrate and treat potential nesting sites. Long-term success will be greater if the parent colony also is located and destroyed. We also believe in using permanent products that will last to keep the infestation from reoccurring.
Carpenter ant infestations usually involve a parent colony and one or more satellite colonies. The parent colony which houses the queen, workers, and brood, requires a moist area and is usually located outside the structure unless a severe moisture problem exists within the building. Satellite colonies house workers, mature broods, and may also contain winged forms. These colonies are often found within structures.
The most effective means of control begins with the location of the main colony and the satellite colonies. Clues in the location of nesting sites include extruded sawdust, foraging trails, and the presence of foraging ants.
Colonies within the structure are controlled by a direct application of our NatureLine PRO®, NatureLine D®, and NatureLine NGB®. These combinations of products provide permanent treatment of the wood and eliminate the colony.
Nests in wall voids often can be accessed through plumbing or electrical wiring with NatureLine® dust. Electrical plates can be removed and an insecticide applied into the wall void along the outside edge of the electrical box. Ants follow wiring and plumbing routes through the structure. If the colony is inaccessible for direct treatment, a 1/8 inch drill bit can be used to make small holes in the walls so an insecticide applicator wand can be inserted for application of the insecticide. Dust formulations are effective against all ants and carpenter ants because the dust adheres to the hairy surfaces of their bodies. As they clean themselves and feed other ants and larvae, the insecticide is spread throughout the colony. This formulation is very effective in wall voids.
A perimeter spray of the structure should also be made with NatureLine PRO®, to disrupt foraging trails and help to prevent re-entry from parent colonies nesting outside the structure. The exterior perimeter spray should include application against the foundation, under the edges of siding, around window and doorframes, and treatment up to 30 feet around the structure.
In structures with a crawl space, the inside of the foundation and all the wood should be sprayed with our permanent wood preservative.
Find the Nests
It may take some long-term observation to find the nest sites. DO NOT DISTURB any ant activity you can see until you call us and have us locate the nests. Disturbing their activity will cause the carpenter ants to develop new routes which may take us longer to find them. If you want to look yourself here are some tips:
- Look for evidence of infestation.
- Check common nest sites in structures.
- Check common nest sites in natural areas or landscapes.
- Locate any trails inside or outside the structure.
- Observe activity along those trails to determine which way the food is moving (distended abdomens, carrying insects).
Other Areas to Check Include:
- � Around sink, dishwasher or shower areas.
- � Hit beams and joists with a hammer, and listen for hollow areas.
- � Look for tiny slits in beams or joists; these are air vents.
- Check attics and crawl spaces.
- Check around fireplace or furnace chimneys which may be warm and moist.
- Remove electrical outlet and light switch plates and look for evidence: pupal skins, sawdust, or ants themselves.
- Check spider webs for evidence (sawdust, etc.)
- Check firewood or lumber especially if it is stacked against the house (a poor practice).
- Check areas hidden by vegetation (prune the backside of evergreen shrubs that may provide shelter for trails and access to the house and increase moisture of the walls.
- Check for evidence of leaking or temporarily plugged (ice, debris) gutters during rainstorms.
- Remove shrubs that block vents or prune them at the base to allow good air flow.
- Check for condensation in the crawl space or attic due to inadequate ventilation.
A natural carpenter ant treatment from All Natural Pest Elimination will provide permanent protection for your home.
Give us a call for a free estimate and inspection.