Experts are warning homeowners that attempting to deal with a wasp nest themselves could disturb the insects and make them more aggressive. The advice is to leave active nests alone and avoid using sprays, as trying to handle the problem without professional help can often make the situation worse.
Why wasps are more aggressive in September
Wasps are common in the warmer months, but their behaviour changes in September as their nests come to the end of their life. During summer, worker wasps spend most of their time feeding the young wasps, or larvae, in the nest. The larvae produce a sugary food that the workers eat.
As summer ends, the queen stops laying eggs, and there are fewer larvae in the nest. This means thousands of worker wasps have to look elsewhere for sugar, which is why they are more attracted to bins, soft drinks, outdoor eating areas and fallen fruit in September.
The common mistake homeowners make
Managing Director at Acorn Environment Services, John Whiteley-Wilkson, said: "September is consistently one of our busiest months for wasp call-outs because colonies are at their largest and worker wasps are actively searching for food outside the nest."
He added: "People often think wasps suddenly become aggressive for no reason, but it's a natural part of their life cycle. As their usual food source disappears, they're forced to search elsewhere, which brings them into much closer contact with people."
Whiteley-Wilkson also urged homeowners to avoid dealing with active nests themselves, saying: "The biggest mistake we see is people trying to block the entrance to a nest or treating it with a household aerosol spray."
How to avoid disturbing wasps
He explained that if wasps cannot use their normal exit, they will look for another route, which could mean finding their way into lofts, wall cavities or even inside the property. Disturbing an active nest can also cause the colony to become defensive, increasing the risk of multiple stings.
If you find a wasp nest, you should avoid blocking or sealing the entrance, and avoid spraying large or well-established nests with household insect spray. The pest control expert also advised against disturbing the nest with garden tools such as ladders or pressure washers, and recommended checking for wasp activity before doing garden work near a known nest.
He said: "Even activities like cutting hedges, strimming or using a pressure washer can create vibrations that disturb an active colony. We've attended plenty of jobs where someone didn't realise there was a nest nearby until the wasps reacted."
If a nest is tucked away in a part of the garden that people rarely use, it may be possible to leave it alone until the colony naturally dies off later in the autumn. However, if it is close to a doorway, patio, children's play area or anywhere people regularly pass, it is worth having it professionally assessed rather than taking unnecessary risks.
