Key takeaways
- Wasps are not angrier in late summer — they are unemployed. Once the queen stops laying, workers lose the sugary secretion the larvae rewarded them with, so they go looking for your jam, cake and beer.
- The colony peaks in size exactly when its own food supply collapses, which is why August and September feel like an invasion.
- Swatting is the worst response: a crushed or cornered wasp releases alarm pheromone that recruits nestmates.
- Never drink from an open can outdoors — a sting inside the mouth or throat is a medical emergency.
- No skin repellent, plant-based or synthetic, is proven to keep wasps away; they are tested against biting insects such as mosquitoes and ticks.
In June you barely notice wasps. By late August you cannot put a slice of plum cake on the garden table without three of them landing on it. It is tempting to assume the wasps have turned nasty — but what has changed is the biology of the colony. Once you understand that, eating outdoors in peace becomes a matter of a few habits rather than luck.
The colony calendar: why late summer changes everything
Common wasps (Vespula vulgaris and Vespula germanica) run an annual colony. A queen starts it in spring, and through early summer the workers do one main job: hunt caterpillars, flies and other insects to feed the larvae. In return, the larvae secrete a sugar-rich fluid that the adult workers live on. Protein goes in, carbohydrate comes back out, and the workers rarely need to bother you.
In late summer that economy shuts down. The queen produces new queens and males, then stops laying. The last larvae pupate, the sugar tap runs dry, and a colony of several thousand workers has nothing left to do and nothing sweet left to eat. They disperse to find carbohydrate wherever it exists: fallen fruit, ivy flowers, bins, ice cream, fizzy drinks and your table.
So the wasps at your picnic are not defending anything and they are not hunting you. They are foragers at the end of a life cycle, competing with you for sugar — and unlike in June, there are an enormous number of them.
Are they really more aggressive?
Mostly they are bolder and more persistent, which feels like aggression. Two things do raise the risk of a sting. First, numbers and closeness: more wasps on food, hands and glasses means more chances to trap one against skin or lips. Second, windfall fruit ferments, and wasps feeding inside it take in alcohol, which appears to make them clumsier and less inclined to fly off when disturbed.
Early summer versus late summer: what wasps actually want
| May – July | August – October | |
|---|---|---|
| What the colony needs | Protein for larvae | Carbohydrate for adult workers |
| Where you meet wasps | Around meat, fish, pet food, the barbecue | Around sweet drinks, cake, fruit, bins, ice cream |
| Number of workers | Rising, still modest | At its yearly peak |
| Typical sting scenario | Disturbing a nest while mowing or hedge-cutting | Trapping a wasp against skin, in a drink or on food |
| What helps most | Knowing where nests are and leaving them alone | Covering food and drink, calm movements, tidy tables |
Why swatting is the worst thing you can do
Social wasps communicate chemically. A wasp that is crushed, squeezed or badly frightened releases an alarm pheromone that tells nearby nestmates to defend — the opposite of what you want at a table surrounded by other wasps. Fast arm movements and blowing at a wasp (the carbon dioxide in your breath reads as a threat) have the same effect on a smaller scale.
- Stay still, or move away slowly. A foraging wasp loses interest in a person within seconds.
- If one lands on your skin, let it walk or brush it off gently with a piece of paper.
- Coach children in advance; panic and flailing is how most childhood stings happen.
- Never block, spray or poke a nest entrance yourself — nest removal is a job for a professional.
How to eat outside in peace: a practical setup
- Keep everything covered until you eat. Food covers, cloches or a tea towel over the bowls make the table far less interesting from the air.
- Ban open cans and bottles. Pour into a glass so you can see what is in it, or use a lidded cup with a straw. Wasps crawl into cans and dark bottle necks unnoticed.
- Wipe hands and faces — especially children’s — after fruit and ice cream. Sugar residue on skin is what keeps wasps circling a person.
- Clear plates and glasses promptly instead of leaving them out all afternoon.
- Move the bin. A closed lid and a few metres of distance removes the biggest wasp magnet in most gardens.
- Try a decoy. A saucer of overripe fruit or jam placed 5–10 metres away, ideally downwind, can draw foragers off the table. It is a folk technique rather than a tested one, but it costs nothing.
- Do not sit under a fruit tree or beside flowering ivy in September — both are busy wasp restaurants.
- Go easy on sweet perfume and hairspray in peak season, and check every drink before you sip.
The same logic applies on a balcony, where table, bin and drinks sit within a metre of each other: the fix is separation and lids, not chemicals.
Hornets are a different story
The European hornet (Vespa crabro) looks alarming but is far less interested in your table than common wasps are. It hunts other insects, flies at dusk and is drawn to lit windows, which is how it ends up indoors. It is also a specially protected species in Germany and Austria: nests must not be destroyed or removed without permission from the local nature conservation authority, and a licensed beekeeper or pest controller can relocate one that is genuinely in the way. The invasive Asian hornet (Vespa velutina), now established in parts of France, Spain, Belgium and Germany, is no more dangerous to people at a distance but does serious damage to honeybee colonies — sightings belong in the national reporting scheme, not in a private extermination attempt.
If you do get stung
Move away calmly, wash the area, apply something cold for 10–20 minutes and raise the limb if it swells. Swelling that spreads well beyond the sting site and peaks after a day or two is usually a large local reaction rather than an allergy. Our full guide to wasp and hornet stings covers the first-aid steps and the allergy red flags — facial or throat swelling, breathing difficulty, dizziness or collapse — that mean calling an ambulance immediately. A sting inside the mouth or throat is an emergency in its own right. Days later, spreading heat, worsening pain or pus is a different problem: see the signs of an infected insect bite.
How incognito® helps
We will be straight with you: no repellent we sell will keep wasps off your cake, and none of the regulated skin-applied actives — DEET, picaridin, IR3535 or plant-based PMD — is tested for that purpose. Wasps are not trying to feed on you, so repellency is not the mechanism.
Where we can help is afterwards, and with the insects that are biting you at the same table. Zap-Ease is a chemical-free device that applies a light mechanical impulse to the skin to take the edge off bites and stings; it was clinically tested at the London School of Hygiene & Tropical Medicine, was effective for 96 % of users and is reusable for up to 1,000 uses or five years. It is not suitable for people with a pacemaker or children under two, and it is never a substitute for medical help in an allergic reaction. For the dusk mosquitoes that arrive once the wasps have gone to bed, our DEET-free insect repellent spray uses PMD (Citrepel®) from Javanese citronella — clinically proven, vegan, biodegradable and recommended against both mosquitoes and ticks.
FAQs
Why are wasps so annoying in August and September?
Because the colony stops rearing larvae, and the workers lose the sugary secretion the larvae fed them. Thousands of adult wasps then hunt for carbohydrate — fruit, drinks, cake and bins — just as the colony reaches its largest size.
Do wasps really become more aggressive in late summer?
They become bolder and more persistent rather than genuinely more aggressive. Stings rise mainly because there are more wasps at close range around food, and a wasp is easily trapped against skin, lips or a glass.
What should I do if a wasp lands on me?
Stay still or brush it off gently with paper. Do not swat or blow at it — a crushed or threatened wasp releases an alarm pheromone that attracts others, and your breath reads as a threat.
Does anything keep wasps away from a picnic table?
Covering food and drinks, closing and moving the bin, clearing plates quickly and wiping sticky hands. A decoy plate of overripe fruit several metres away can help. Skin repellents do not work on wasps.
Is it dangerous to drink from a can outdoors?
It can be. Wasps crawl into open cans and dark bottles unnoticed, and a sting inside the mouth or throat can swell enough to obstruct breathing. Pour drinks into a glass or use a lidded cup.
Can I remove a wasp or hornet nest myself?
No — disturbing a nest is how the worst multiple-sting incidents happen. In Germany and Austria the European hornet is protected, and its nest may only be removed with official permission, normally by a licensed specialist.
Sources
- NHS — Insect bites and stings
- NHS — Anaphylaxis
- US EPA — Skin-Applied Repellent Ingredients
- ECDC — Protective measures against mosquitoes
This article is general information, not medical advice. If you have a known venom allergy, carry your adrenaline auto-injector and follow your doctor’s emergency plan. Always read the product label before use.