After the Treatment

The first day

Fewer, Then Confused, Then None

Activity usually falls sharply within a few hours. What continues for a while is returning foragers — wasps that were away from the nest at the time, coming back to a colony that no longer works.

They cluster around the entrance, fly erratically, and can look more agitated than before the treatment. That is expected. They have nowhere to go and no colony to return to, and they die off over the following day or two.

Keep away from the entrance for the rest of that day, keep pets off that part of the garden, and leave the nearest windows shut. By the second or third day it is normally over.

Images on this page are illustrations only.

The first week

What Is Normal and What Is Not

Normal: a few live wasps around the entrance getting fewer each day; dead wasps on the ground or on a window sill below the nest; nothing at all after two or three days.

Normal in a loft: finding dead wasps for a while afterwards, and a faint smell if the nest was large. Both pass.

Not normal: steady two-way traffic still going into the same entrance a week later, at the same rate as before. That is what the guarantee is for — if the wasps return to the same nest location, the firm re-treats at no extra cost. Ring rather than wait.

Worth distinguishing from a second nest. It is not unusual to have two on one property, and a second nest at a different entrance is a separate job rather than a treatment that failed.

Clearing up

Dead Wasps, and the Nest

Dead wasps can be swept or vacuumed up normally. Wear gloves if you are picking them up by hand, not because of any residue but because a dead wasp's sting can still penetrate skin if you press on it.

The nest, as elsewhere on this site, is usually left. It is used for one season only, nothing moves into it, and cutting it out of a structure achieves nothing. Where it is somewhere it cannot stay it can be removed once dead.

The one case for taking a nest out is a loft used for storing clothes, fabric or paper. An abandoned nest is slowly worked over by the larvae of small beetles and moths feeding on the paper and the remains inside, and while that is contained and harmless in a wall cavity, you would rather it was not happening next to stored textiles.

Before next spring

The Job Worth Doing in Winter

You will not get the same colony back. You may well get a new one in the same place, because a queen looking for a site in April is looking for the same qualities that made it a good site last year.

So the useful window is late autumn to early spring, when there is nothing alive in there:

• Mesh the airbricks and weep holes with fine stainless mesh — over them, never blocking them, because they ventilate the cavity.
• Repoint failed mortar and seal gaps where pipes and cables pass through walls.
• Replace missing or damaged soffit and fascia sections, and fit a guard to any vent that has lost one.
• Check the shed and outbuilding cladding for gaps at the eaves.
• Empty and clean bird boxes over winter.

None of that is urgent and none of it needs doing in August. It is a winter afternoon's work and it removes the site rather than the colony.

Short answers

Wasp Questions

Going further

Wasp Guides