Wasps in Ontario

Wasps are most noticeable in late summer, when they hover around drinks and food. Most stings happen when people get too close to a nest. Here is how to identify what you are seeing and stay safe.

Is it a wasp, hornet or bee?

Wasps have slim bodies, a narrow waist and smooth, shiny skin. Yellowjackets, common in Ontario, are black and yellow. Bees are rounder and fuzzier. Hornets are larger wasps.

Bees vs wasps: why it matters

Bees are important pollinators. A nest in a wall might be bees, not wasps. Health Canada notes wasps can sting more than once, unlike bees. Because the treatment differs, have a professional identify the insect before anyone treats a nest. Please do not treat bees.

Where do wasps nest?

The ROM notes that queens often start nests in wall spaces, tree stumps or underground. You may also see them in shrubs, under eaves and in sheds. A steady stream of wasps flying to and from one small opening is a strong sign.

Why are wasps worse in late summer?

In August, the queen slows down egg-laying. With fewer larvae to feed, workers have more free time and go looking for sweet foods like pop and fruit, and for meat. That is why they appear at picnics and patios just when people spend the most time outdoors.

Will wasps leave in winter?

Yes. The ROM says most workers die after the first frost, and none survive an Ontario winter. New queens shelter somewhere protected and start new nests in spring. That is why wasp season is roughly July to September.

How serious are wasps?

For most people, a sting is painful but passes. Health Canada says ice packs or a baking soda paste can soothe a sting. Severe allergic reactions are rare but can be fatal. Seek medical care right away for unusual swelling, itching, dizziness or trouble breathing.

What to do if you are stung

• Move away from the area calmly.
• Apply an ice pack or baking soda paste.
• Get medical help straight away if you notice any of the warning signs above, or if you know you are allergic.

What should I do now, and what should I avoid?

Do:

• Stay calm and let a wasp fly off, or brush it away gently.
• Keep your distance from any nest, and keep children and pets away too.
• Keep food and sweet drinks covered outdoors.

Avoid:

• Swatting. The ROM says threatened wasps release pheromones that call others to join in.
• Spraying, burning or knocking down a nest.
• Blocking a nest opening in a wall.

Health Canada says removal can be dangerous because a large group may attack, and that professional help is recommended. We agree: call a professional.

How does professional treatment work?

We follow four steps, explained in our integrated pest management guide:

1. Inspect. Find the nest and see how it is placed.
2. Identify. Confirm the insect, so bees aren’t treated by mistake.
3. Treat. Deal with the nest.
4. Follow-up. Check for continued activity.

Our wasp nest removal page has the details. We serve homes in cities such as Oakville and Vaughan. Ants are another warm-weather pest; see our page on ants.

Get a free quote

Request a free quote and quote details reach you within 30 minutes. You can also call using the number at the top of the page.