Wasp Nests: Why You Must Never Block the Entrance Hole Category: Wasps / Safety Advice

ByNewmarket Pest Solutions

The Worst Thing You Can Do to a Wasp Nest

It is a warm afternoon in late Spring. You are in the garden and notice a steady stream of wasps flying in and out of a small hole in your brickwork or under the roof tiles.

Your first instinct is logical: “If I block the hole, they can’t get out, and they will die.”

You reach for the expanding foam, silicone, or even cement, and you seal the gap tight.

Please, do not do this.

At Newmarket Pest Solutions, we attend dozens of emergency call-outs every summer where a homeowner has blocked a nest entrance. In almost every case, the situation has gone from a minor nuisance outside to a major emergency inside.

Why Blocking the Hole Fails

When you seal the entrance to a wasp nest, you do not kill the colony. You simply trap thousands of angry wasps inside a confined space.

Wasps are incredibly strong and determined diggers. If they cannot get out the way they came in, they will look for another exit. Since the outer wall is now blocked with hard cement or foam, they turn inwards.

The only thing separating a nest in your wall cavity from your bedroom is often a thin layer of plasterboard. Trapped wasps can chew through plasterboard in a matter of hours.

We have seen terrifying situations where a customer blocked a hole outside, only to wake up the next morning to find hundreds of confused, aggressive wasps buzzing around their bedroom.

The “Traffic” Sign

If you see wasps entering and leaving a specific spot, that is the “front door.”

Professional pest controllers need that door open.

  • How We Treat It: We use a specialist insecticidal dust. We don’t try to find the nest itself (which is often hidden deep in the loft or wall).

  • The Trojan Horse: We inject the dust into the entrance hole. The worker wasps fly in, get coated in the dust, and carry it deep into the heart of the nest.

  • The Result: The colony is eliminated safely from the inside out within a few hours.

If you block the hole, we cannot treat the nest effectively, and you may end up needing a builder to remove part of your ceiling to get to them.

When to Call Us

You will start seeing the “Queen Wasps” waking up in April/May, but the actual nests usually become a problem from June onwards.

  • April/May: You see one big wasp (the Queen). She is looking for a home.

  • June/July: You see a steady stream of smaller wasps. The nest is established.

  • August/Sept: The wasps become aggressive and “drunk” on fermenting fruit.

Stay Safe

If you find a nest, keep children and pets away. Do not wave your arms or try to spray it with shop-bought foam (which requires you to get dangerously close).

Spotted a nest? Leave the hole open and call the professionals. Contact Newmarket Pest Solutions. We can usually treat wasp nests in Newmarket, Red Lodge, and Brandon on the same day.

Similar Posts