What a long wet winter, below is information on Camponotus Modoc, carpenter ants, and one of the worst pest in Pacific Northwest.
Presence of few foraging ants in the home, or 1 or 2 winged queens during swarming times does not mean you have an infestation. These foragers may merely be scout ants seeking food, nesting sites or queens that have flown in an open door. Particularly in May and June when the very weak sighted females are more commonly swarming and breeding do you see this occurring.
Foraging ants that have been seen entering homes along telephone wires, along branches touching the roof, hoses or pipes,even from ground trails that come under a door. In such cases, greater numbers above 15-20 indicate the house may be a nesting area.
If ants are coming in, there may be a nest somewhere outside of the building but eventually they may establish satellite colonies in some part of the structure. Be certain they are Carpenter ants and not another species of ant, termite, yellowjackets, spider or something else.
1.0 Evidence of Infestation(s)
- Presence of ants (workers or winged reproductives): An occasional ant may be a scout looking for food and may not indicate the presence of a nest, but continuous or numerous ants are a sign of nesting.
- Sawdust: Accumulating in piles, caught in spider webbing, paint, cracks and crevices; has a finely-shredded appearance. Do not confuse with small sawdust from construction or painting. It looks quite similar and is called “Frass”.
- Trails: Detailed discussion later.
- 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 the golden buprestid beetle or yellowjacket nesting in wall voids produce sounds and using tools like a stethascope, spotting/inspection camera’s/mirrors are what pro’s like Tristan use in nearly all cases.
Type of House Likely to be Attacked
Research shows common elements accompanied by infestations. Although other types of structures are attacked, most infestations were in residential homes with the following characteristics:
- Wood frame
- Crawl space
- Cedar or plywood siding
- Moderately to gently sloping roof
- 5-25 years of age
- Vegetation (trees and shrubs) surrounding the house
- *”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.
Structural Information on Nests Location
Most nests of C. modoc, the most common Sea to Sky carpenter ant, which could be found were associated with (in order of frequency):
- Outside walls and voids – 35%
- Attic – 21%
- Ceilings – 19%
- Crawl space – 19%
- Other sites (including interior walls, roof, sill plate, and supports in crawl space and stacked lumber) -6%
*Other researchers have reported that ants show a light preference for moist wood with decay fungi but that sound wood is also mined.
Most Commonly Nests have been found in the following area’s:
- Porch pillars
- Support timbers
- Window framing and sills
- Casings of houses, garages and other buildings
- Drawers of dressers and cabinets
- Behind books
- In hollow doors
- Under floors
- Attic spaces
- Buried wood, stumps or construction debris
Nest Location Outside Structures (Natural Areas or Landscape)
- Forest (within 50 meters of home) – 27%
- Live trees (excavate heartwood; enter by knotholes, wounds, etc.) – 17%
- Dead trees, stumps or logs, buried wood – 16%
- Wood debris – 8%
- Decorative wood in landscape – 7%
- Stacked lumber – 3%
- Firewood – 3%
1.1 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 after significant growth has occurred.
The parent colony contains the queen, young larvae and workers, while the satellite contains the mature larvae, pupae, workers, and/or winged reproductives.
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).
In this particular study, in Washington State, houses had from 1-3 colonies with an average of 1.3 however in Whistler we have seen as many as 13 different Modoc colonies in larger more established nest’s and colonies.
If the parent nest is not found, the ants can reestablish satellite colonies after the pesticides have become inactive or establish new colonies in untreated areas of the house so it is important to treat entire area’s of the structure as well as arrange follow ups.
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, nest or area, into a jar:
- Ants from the same parent colony coexist peacefully.
- Ants from different colonies fight.
1.2 Ant Trails
Ants move along definite trails by following a chemical scent or visual clues left by previous colony member. 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 the best they can to get through.
1.3 Carpenter Ant Trail Locations
Trail Location Outside the Structure
Ants follow natural contours mostly due to protection from Predictors. 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 or 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, 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 Information Along Ant Trails
- Ants are generally active along ant trails in western Washington and British Columbia 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.
Determining if Ants are returning to nests:
- 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 rather than the satellite. Ants carrying larvae or pupae (papery cocoons) are moving from the parent to satellite colony.
Activity, therefore ease in following a trail, is greatest after sunset (roughly between 10 p.m. to 2 a.m.). A red light disturbs ants less than white light.
Trails are difficult to locate since they may disappear under boards, sidewalks or go underground, through sticks, logs, mulch and so on
While gardening or working in the yard keep watching for clues but don’t get too trigger happy and spray the trail, or you will have to start over if you want to find the nest. If you decide to call us make sure you let us know all the information about chemicals and exclusion methods used in the past and currently.
1.4 What Carpenter Ants Eat
Carpenter ants cannot eat solid food. They have a very long, exceptionally thin esophagus’s (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.
1.5 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 small home 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 become dormant. No feeding occurs during the winter months (November, December, January).
- The dormant phase 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, or season, is very low (with only 1 or 2 dozen workers).
- It took about 3 seasons to produce even a few larger workers in Dr. Hansen’s studies. 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.
*Take into consideration most of this research was performed in a lab
1.6 Other Interesting Facts
- 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.
- At any one time only a small percentage (1%-3%) of the ants are outside the nestforaging for food and water.
- The queen and workers can eat their own eggs and smaller larvae, if the food supply is low it severely stresses the colony and retards its growth.
1.7 Structural Carpenter Ant Management
Finding parent colonies and the satellite colony (colonies) in the surrounding landscape is crucial to successful structural control of carpenter ants.
Many pest control companies either:
A) Drill and inject the entire house because it is faster and at less costly to the homeowner than it would take to locate and treat the nest areas.
B) Starve out the ants by spraying only the perimeter (attic, crawl space, and foundations) at monthly intervals for a year or so.
Using as little if any chemicals, our success and experience is that long term results will be greater if the parent and satellite colony (colonies) are located and destroyed. Since 1962, The National Pest Control Operator’s Association has recommended this, as well as formation of Integrated Pest Management under the Nixon Government in 1972. It should be noted that despite Dr. Hansen’s, the Washington State Pest Control Association’s, and other’s recommends of “careful inspection”, and that “a professional attempt be made to penetrate and treat potential nesting sites”,many companies are still using treatment technologies from the 1960′s.
2.0 Approaches to Control:
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.
2.1 Hunting for Carpenter Ant Nests on the Wet (West) Coast
It may take some long-term observation to find the nest sites. DO NOT DISTURB any ant activityunit you can see and have located the nests. Disturbing their activity will cause the ants to develop new routes which may take you much longer to find. Here are the best useful tips at doing that:
- Look for evidence of infestation like frass and other’s spoken about previously.
- 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).
- Observe after sunset with red light.
Other Good Areas to Check Include:
- Around sink, dishwasher or shower areas.
- Hit beams and underflooring 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, ants.
- 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 back side of evergreen shrubs which 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.
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