How wasps get into a wall
Walls are full of small openings: gaps around waste pipes, boiler flues, cables, vents and old mortar joints. A queen finds one in spring and starts the nest inside the cavity, where it is warm, dry and untouched.
Cavity walls and the voids behind cladding or render are the usual spots. The nest can grow to a serious size before you notice anything.
Signs of a cavity nest
The clearest sign is a steady flight line to one point on the wall: wasps arriving every few seconds and disappearing into a gap. You may also hear a faint rustling or crackling inside the wall, especially at night when the house is quiet.
In late summer, a large cavity nest can stain plaster or soften it where the nest presses against the inner wall. If you see a damp-looking patch with wasps nearby, keep away from it and call us.
- A steady stream into one gap in the brickwork
- Rustling or crackling inside the wall
- Wasps appearing indoors near that wall
- A soft or stained patch on plaster in late summer
What not to do
Do not fill the gap, drill into the wall or inject foam. Trapped wasps chew through plasterboard into your rooms, and a half-killed colony in a wall is far worse than a live one.
Do not bang on the wall to "scare them off" either. It does not move the nest, and it puts the colony on alert.
How we treat a cavity nest
We treat the external entry point, applying the treatment where the wasps go in. There is no need to open the wall. The workers carry the treatment through the cavity to the nest itself.
As with every nest, the price is £125 fixed, with no call-out fee and a free revisit if the nest is still active after the first treatment.
Preventing a repeat
Once the colony is dead, the old nest is harmless and will not be reused. You can leave it in the wall.
In winter, seal the gaps the wasps used: around pipes, cables and in mortar joints. Do it after the nest is dead, never before, and you make next spring much harder for the queens.
Wall cavity nests: common questions
Do you have to cut into the wall?
No. We treat the entrance from outside. The nest stays in the wall and causes no harm once the colony is dead.
Can a cavity nest damage my house?
Rarely. A very large nest can soften or stain plaster beside it in late summer. Treating early avoids this, and the fix is usually a simple patch and repaint.
Why do I hear them at night?
The colony is quietest at night, and so is your house, so the rustling of the nest carries further. It is normal and not a sign the wasps are active in the dark.