Why Wasps Are Worse in Calgary During Late Summer
If you’ve lived in Calgary for a while, you’ve probably noticed that wasps seem to become much more aggressive and noticeable toward the end of summer. You might be enjoying a backyard BBQ or a patio drink when wasps show up uninvited. But why is this such a common experience in August and September?
It’s Not Just Your Imagination—They Really Are Worse
Wasps are around all summer, but their behaviour changes drastically later in the season. In spring and early summer, most wasps are busy building nests and feeding larvae. They’re mainly focused on survival and colony growth. But by late summer, the dynamic shifts.
The Wasp Colony Life Cycle
Here’s a simplified breakdown of how it works:
Spring: A single queen starts a nest.
Early Summer: Workers hatch and help build the colony.
Mid-Summer: The colony thrives and reaches peak numbers.
Late Summer/Fall: The queen stops laying eggs, and the colony begins to break down.
By late summer, the worker wasps no longer have larvae to feed, and their role in the colony becomes less defined. Without a job and without a queen directing activity, wasps become more aggressive and start foraging for sugary foods—like your pop, fruit, or desserts.
Why Climate Makes It Worse
Calgary’s hot, dry summers followed by sudden cooling in early fall make the seasonal shift abrupt. This leads to wasps acting erratically over a short period, increasing interactions with people.
What You Can Do
Cover food and drinks outdoors.
Seal garbage bins tightly.
Avoid swatting at them—it triggers aggression.
Call a professional if you see high activity near your home or discover a nest.
Late summer is also the best time to schedule preventive pest control for next spring. Reach out to us for advice or service options tailored to Calgary homes.
