If you’ve noticed large black ants around your yard or firewood pile, you’re not imagining things. Alberta — especially forested communities like Redwood Meadows and Bragg Creek — is home to carpenter ants, and they’re more common than many homeowners realize.
Unlike termites, carpenter ants don’t eat wood — they excavate it to build nests. And the presence of these ants can be a major warning sign that your tree is already suffering from interior decay or structural failure.
There are over 1,000 species of carpenter ants globally, but in our region, we typically see a black variety — not the red ants people often associate with this pest.
Carpenter ants prefer to nest in dead, damp, or decaying wood. In Alberta, they particularly love:
If you’re seeing ants around a tree, it may already be internally compromised.
One of the most important takeaways is this:
Carpenter ants don’t cause decay — they exploit it.
They move into trees that are already in decline, often speeding up the process by weakening the internal structure. That said, their presence is a red flag that shouldn’t be ignored.
Keep an eye out for:
If you’re noticing any of these signs — especially near structures or play areas — it’s time to schedule a tree risk assessment.
During a routine assessment, our team found a white spruce showing signs of carpenter ant activity. After removing some soil at the base, we discovered a void running deep into the trunk.
Once safely removed, we found:
Had this tree failed, it would’ve come down directly onto the client’s garage — a disaster narrowly avoided thanks to the homeowner’s decision to get it assessed early.
Not every ant in your home is cause for alarm. Here’s a quick guide:
Ant Type | Concern? | What to Do |
Large, black, no wings | Low | Probably a field ant looking for food |
Winged black ants in numbers | Medium–High | Possible indoor nest or wall void infestation |
Sawdust piles inside | High | Likely active carpenter ants — call an exterminator |
Outdoor wood with visible ants | High | Tree or woodpile likely infested — assess tree health |
Pro Tip: Carpenter ants can occasionally move from trees into home structures. Keep firewood stacked away from buildings and maintain dry, well-ventilated crawlspaces.
Are carpenter ants dangerous to trees?
Not directly — but they accelerate decay and signal that a tree may already be structurally compromised.
Can carpenter ants kill a healthy tree?
Rarely. They prefer trees that are already in decline due to fungus, pests, or poor soil conditions.
How do I know if a tree is hollow?
Knock on it. A hollow, drum-like sound is a clue. Red Mountain Rigging uses sounding techniques and visual inspections to detect risk.
What should I do if I find ants in firewood?
Burn it quickly. Don’t store infested wood indoors. Ants won’t survive long in dry environments.
Do carpenter ants infest homes in Alberta?
Yes — especially if they move from a nearby tree. Watch for winged ants, sawdust, and repeat sightings.
If you’re seeing ants in your yard, near your firewood, or climbing up a tree — especially a white spruce — don’t ignore it. These insects are nature’s decay detectors, and their presence often means your tree is already compromised.
Red Mountain Rigging offers FREE, no-obligation tree assessments in Calgary, Redwood Meadows, and surrounding areas. Let us inspect your trees before nature does it for you — the safe way.
Phone: (825) 945 8733
Email: Redmrig@outlook.com
We would love to speak with you!