Foragers or a Nest?
A foraging wasp will work several hundred metres from home, so wasps at an outdoor table in late August may have no nest anywhere near. What they have found is sugar, and they will keep coming back to a reliable source in numbers that look like an infestation without being one.
The test is the same as anywhere: look for a route. A steady two-way stream in and out of one fixed point is a nest. Wasps arriving from several directions and leaving in several directions are foragers, and treating the building will not change that at all.
What Draws Them to a Table
- Open bins and, above all, bins with sweet waste in them
- Glasses and cans left standing — a can is the classic, because a wasp goes inside it
- Fallen fruit under a tree, which is the strongest draw in any garden
- Uncleared plates and anything sticky on a table or the ground
- Recycling that has not been rinsed
Dealing with those does not remove wasps from the area but it does stop your table being the best thing on offer, which in practice is most of the difference between a nuisance and an afternoon indoors.
If There Is a Nest as Well
Where there is a nest on the property it gets treated, and the difference outdoors is usually obvious within a day. Where the nest is on a neighbouring property, treating yours achieves nothing and we will tell you that rather than take the money.
A nest over a seating area, a smoking shelter or a doorway is worth treating outside the hours people use it, so the brief spike in activity afterwards does not land in the middle of a busy afternoon.
Not Swatting, and Why It Matters
A crushed or threatened wasp releases an alarm pheromone that draws others and puts them on the defensive. Waving and swatting is the single most reliable way to turn one wasp at a table into six. Stay still, let it settle, and move the food rather than the wasp.
The same applies to anything left standing. Cover drinks, use a glass rather than a can, and check before drinking — most of the stings around outdoor eating happen in the mouth or on the lip, and those are the ones that matter.