Carpenter Ants This Spring: Spot Them and Stop Them

Donna M
Apr 23
4 min read

Spring is in the air! The sun seems brighter, the trees are getting greener, and the days are getting longer. Here on Vancouver Island, that seasonal shift often comes with a mix of relief—and a few unwelcome guests.

You and your family aren’t the only ones looking forward to warmer days. Around this time of year, many homeowners start noticing large black ants creeping around their property—or even inside their homes. These are often carpenter ants waking up from their winter dormancy.

Let’s take a closer look at why they appear, how to spot a potential problem early, and what you can do to protect your home.

The Annual Carpenter Ant Cycle

Understanding carpenter ant behavior starts with their yearly cycle.

During the summer and fall, ants are highly active outdoors, foraging for food to sustain their colonies. Occasionally, they may wander indoors in search of crumbs—but this doesn’t necessarily mean there’s a nest inside your home.

Call Sentry Pest Control Today!

In winter, ants enter a dormant phase called diapause. During this time, their metabolism slows significantly, and colony activity drops to a minimum.

As spring arrives—especially in the mild coastal climate of Vancouver Island—carpenter ants become active again. They begin searching for food and water, which is why you may suddenly notice them in kitchens, bathrooms, or along windowsills.

Smaller ant species, like pavement ants, typically don’t appear until later in May or June.

How to Identify Carpenter Ants

Winged Carpenter Ant — Some Carpenter Ants Have Wings - Some Don't

If you see ants around your home or property, how do you know if you are dealing with carpenter ants as opposed to one of the other types of ants found on Vancouver Island? (check out our blog Ants on the Island for more info on all the ants you can find here!). Here is how to know you’re dealing with carpenter ants:

Large Size: carpenter ants are among the largest ants you’ll see. Workers typically range from 6 mm to 13 mm (¼ to ½ inch) but the queen can be even larger.
Smooth, Rounded Thorax: when viewed from the side, their thorax (middle section) has a smooth, evenly rounded curve. This is one of the most reliable identifiers.
Single Node (Petiole): between the thorax and abdomen, carpenter ants have one small, upright node. Some other ants have two nodes—this helps distinguish them.
Elbowed Antennae: their antennae are bent (elbowed) rather than straight. This is typical of ants, but still useful when comparing to termites.
Wings: known as "swarmers," only reproductive carpenter ants (queens and males) have wings, which they use to fly and establish new colonies, typically in spring.

Signs You May Have a Carpenter Ant Problem

Seeing a single ant doesn’t always mean trouble—but recurring sightings, especially in early spring, can signal something more serious.

Carpenter ants on wood — Carpenter Ants Leave Clues That They are Here

Watch for these warning signs:

Large black ants indoors (a strong indicator of carpenter ants)
Visible ant trails, especially in the evening or at night
Sawdust-like debris near baseboards, window frames, or doorways (a result of tunneling)
Winged ants emerging indoors, often from cracks or walls
Ant activity on upper floors of your home
Faint rustling or cracking sounds inside walls
Seeing ants indoors before noticing them outside

If you’re experiencing these signs year after year, there’s a good chance a colony is nearby—or already inside your home. It is best to call a pest management company like Sentry Pest Control to identify, confirm, and mitigate your carpenter ant suspicions.

The Damage Carpenter Ants Can Cause

Unlike termites, carpenter ants don’t eat wood—but they do excavate it to build nests.

Once a queen establishes a colony, it can grow rapidly. Over a few years, a single colony can expand into multiple satellite colonies throughout your home’s structure.

Wood that has been damaged by carpenter ants — Signs of Carpenter Ants

This tunneling can weaken wooden supports, leading to costly structural damage if left untreated. On Vancouver Island, where moisture levels can be higher, homes may be especially vulnerable to carpenter ants seeking damp wood.

Protecting Your Home

The best defense against carpenter ants is early detection and prevention—especially in early spring.

Here are some key steps homeowners can take:

Seal Entry Points: Inspect your home for cracks and gaps around windows, doors, and the foundation. Even small openings can act as entryways.
Manage Moisture: Carpenter ants are drawn to damp wood. Fix leaky pipes, improve drainage, and ensure proper ventilation in crawl spaces and attics.
Trim Vegetation: Branches and plants touching your home can act like bridges for ants. Keep vegetation trimmed back from exterior walls.
Get Rid of Decaying Wood: Chopped down tree stumps and piles of old wood are prime real estate for carpenter ants. Get old wood out of your yard as best you can.

Contact Sentry Pest Control for Assistance!

Call a Professional

If you suspect carpenter ants have established a colony in your home, it’s important to act quickly. A professional pest control service like Sentry Pest Control can assess the situation and recommend targeted treatment options.

Professional inspections ensure: