Carpenter Ant
Camponotus spp. (C. pennsylvanicus, C. modoc)
Anatomy
Identification
Distinguishing Features
- Single node (petiole) between thorax and abdomen
- Evenly rounded thorax in profile
- Heart-shaped head when viewed from front
- Workers vary significantly in size (polymorphic)
Similar Species
- Pavement ants are much smaller (2-4mm) and create visible soil mounds
- Black garden ants are smaller (4-6mm) with less pronounced size variation
Biology
Lifecycle
Complete metamorphosis: egg → larva → pupa → adult. Colony maturation takes 3-6 years.
Diet
Proteins (insects, meat) and sugars (honeydew, plant nectar). Do NOT eat wood.
Nesting
Excavate galleries in damp or decaying wood (do NOT eat wood). Key Concept: 90% of indoor infestations are 'satellite colonies' containing workers and older larvae/pupae. The 'parent colony' with the queen and eggs is usually outside in a tree stump or landscape tie up to 90m away.
Complete metamorphosis takes 6-12 weeks depending on temperature.
Signs of Infestation
Frass with insect parts
Sawdust-like debris. Unlike termite droppings (which are uniform pellets), carpenter ant frass looks like pencil shavings and often contains distinct bits of dead insects.
Rustling sounds in walls
Audible at night as workers excavate; sounds like crinkling cellophane
Winged ants indoors (May-July)
Swarmers emerging inside indicate established indoor colony
Hollow-sounding wood
Tap structural wood with screwdriver handle; hollow sound suggests galleries
Where They Nest
- Window and door frames exposed to moisture
- Roof areas near ice dams or damaged shingles
- Bathroom and kitchen walls near plumbing
- Decks, porches, fence posts in soil contact
- Firewood stored against house
Distribution in Canada
Found in all provinces. Highest pressure in British Columbia, Ontario, and Quebec.
Active Season
Most active May through September. Swarmers emerge May-July.
House Types at Risk
This pest is commonly found in these home types
Bungalow / Ranch
High RiskSingle-story with soil-adjacent wood framing. Moisture accumulation at sill plates creates ideal nesting conditions.
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Crawlspace Foundation
High RiskAccessible wood framing in humid crawlspace environment. Direct path from soil to structural wood.
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Walkout Basement
High RiskEarth-contact walls on one or more sides create moisture pathways and wood-soil proximity.
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Two-Story
Moderate RiskMore complex roof structure with potential moisture traps. Ice dams can damage wood at eaves.
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Split-Level
Moderate RiskMultiple roof junctions and varied foundation levels create moisture vulnerability points.
View house details →Prevention
- Eliminate moisture sources (fix leaks, improve ventilation)
- Maintain 15cm clearance between soil and wood siding
- Store firewood at least 6m from home, elevated off ground
- Trim tree branches that contact or overhang structure
- Seal gaps around pipes and cables entering home
Professional Treatment
Licensed technicians use targeted baits and residual treatments to eliminate parent and satellite colonies. DIY treatments rarely succeed because the queen is typically in the outdoor parent colony.
Get Ant Control ServiceFrequently Asked Questions
What does a Carpenter Ant eat?
Proteins (insects, meat) and sugars (honeydew, plant nectar). Do NOT eat wood.
Where does a Carpenter Ant nest?
Excavate galleries in damp or decaying wood (do NOT eat wood). Key Concept: 90% of indoor infestations are 'satellite colonies' containing workers and older larvae/pupae. The 'parent colony' with the queen and eggs is usually outside in a tree stump or landscape tie up to 90m away.
When is a Carpenter Ant most active?
Most active May through September. Swarmers emerge May-July.
What are the signs of a Carpenter Ant infestation?
Frass with insect parts: Sawdust-like debris. Unlike termite droppings (which are uniform pellets), carpenter ant frass looks like pencil shavings and often contains distinct bits of dead insects. Rustling sounds in walls: Audible at night as workers excavate; sounds like crinkling cellophane. Winged ants indoors (May-July): Swarmers emerging inside indicate established indoor colony. Hollow-sounding wood: Tap structural wood with screwdriver handle; hollow sound suggests galleries.
How can I prevent a Carpenter Ant infestation?
Eliminate moisture sources (fix leaks, improve ventilation). Maintain 15cm clearance between soil and wood siding. Store firewood at least 6m from home, elevated off ground. Trim tree branches that contact or overhang structure. Seal gaps around pipes and cables entering home.
How is a Carpenter Ant treated?
Licensed technicians use targeted baits and residual treatments to eliminate parent and satellite colonies. DIY treatments rarely succeed because the queen is typically in the outdoor parent colony.
Scientific Classification
- Kingdom
- Animalia
- Phylum
- Arthropoda
- Class
- Insecta
- Order
- Hymenoptera
- Family
- Formicidae
- Genus
- Camponotus
