How to Deal With a Wasp Infestation in Canberra

Wasp infestations are one of Canberra’s most dangerous pest emergencies. Unlike bees, wasps can sting repeatedly, and European wasps in particular are highly aggressive when their nest is disturbed — even vibrations from a lawnmower can trigger a mass attack.

Canberra’s warm, dry summers create perfect conditions for wasp colony growth. European wasps — the most problematic species in the ACT — were first established in Australia in the 1970s and have since become a significant public health concern. Unlike native paper wasps that build small, exposed nests, European wasps construct their nests in concealed locations: underground in old rodent burrows, inside wall cavities, in roof spaces, and inside retaining walls. This concealment makes them particularly dangerous because you may not know a nest exists until you accidentally disturb it while gardening, mowing, or doing renovations.

A European wasp colony starts in spring with a single queen building a small nest. By late summer, that nest can house 5,000-15,000 workers and measure over 30cm in diameter. The wasps become increasingly aggressive as autumn approaches and food sources decline, leading to more encounters at outdoor dining areas, rubbish bins, and pet food bowls. Each worker can sting multiple times — unlike honeybees, their stinger has no barb and doesn’t detach. For the estimated 3-5% of people with venom allergies, even a single sting can trigger life-threatening anaphylaxis requiring immediate epinephrine and emergency medical care.

Identifying Wasps in Canberra

What To Do If You Find a Wasp Nest

Professional wasp nest removal is the only safe option for European wasp nests. Licensed pest controllers use full protective suits, industrial-grade insecticidal dusts or liquids, and specialised equipment to treat nests in difficult locations. The treatment is typically applied at dusk or dawn when most workers are inside the nest, maximising the kill rate. For underground nests, the entrance is treated with insecticidal dust that workers carry deep into the colony. Wall cavity nests are treated by drilling a small hole and injecting dust or foam directly into the void.

After treatment, it’s normal to see wasp activity for 24-48 hours as returning foragers find the treated nest. These workers will die within hours of contact with the treated surfaces. The nest should not be removed for at least 48 hours to ensure all returning wasps are killed. Your pest controller will advise on when it’s safe to re-enter the area and whether a follow-up visit is needed for large or difficult-to-access nests.