European hornets are big. Very big compared with the wasps most people are used to seeing.
Add the deep, loud buzzing noise they make and it is easy to understand why finding one flying around your bedroom at night can be frightening.
The reassuring part is that European hornets are generally much more docile than their size suggests. They are a native species and, if a nest is somewhere out of the way and is not causing a problem, there may be no reason to disturb it at all.
Problems tend to arise when they nest in or close to buildings, repeatedly enter occupied rooms or establish a nest somewhere people need to pass regularly.
If you are not sure what you are looking at, we can help identify it and explain whether anything actually needs to be done.
Think you have European hornets? Call Guardian Pest Control or send us an enquiry.
Why do I keep getting hornets in the house at night?
This is one of the most common European hornet problems we hear about.
Unlike most of our other social wasps, European hornets will fly and hunt in very low light and can be active at night. They are also strongly attracted to artificial lights.
On a warm evening the bedroom window is open, the light is on and suddenly an enormous hornet appears in the room.
Sometimes it is one. Sometimes people tell us they are being plagued by them night after night.
It does not necessarily mean the nest is inside the house. There may simply be a colony nearby and the hornets are being drawn towards the illuminated window.
Closing windows before switching bright lights on, drawing curtains or blinds, or fitting an insect screen can make a considerable difference.
If hornets are repeatedly appearing from the same direction or you can see regular activity around part of the building, it may be worth investigating further.
What does a European hornet look like?
The European hornet, Vespa crabro, is Britain’s largest native social wasp.
It is considerably bigger and heavier-looking than a common or German wasp, with reddish-brown colouring around the head and thorax and a strongly yellow and brown patterned abdomen.
But there is another feature we find particularly useful.
Look for the yellow Alice band
Look at the top and back of a European hornet’s head.
There is a very noticeable yellow band of colour which we describe as its little yellow “Alice band”.
Once you know what you are looking for, it is an extremely useful field clue and one of the features we use when identifying European hornets.
European hornet or yellow-legged hornet?
This distinction is important because the two insects are regularly confused.
The yellow-legged hornet, Vespa velutina, is the invasive species being monitored in Britain. You may still hear it referred to by its older commonly used name, the Asian hornet.
One of the biggest misconceptions is that the yellow-legged hornet must be enormous.
It is not.
The yellow-legged hornet is actually smaller than our native European hornet.
European hornets are generally much more yellow and reddish brown.
Yellow-legged hornets are much darker, with a dark brown or almost black body, yellow ends to the legs and a prominent yellow or orange band towards the rear of the abdomen.
There is another useful clue.
European hornets can fly at night and are attracted to lights. Yellow-legged hornets are not normally active at night.
So if a very large, reddish-brown and yellow hornet is repeatedly arriving at your illuminated window after dark, a European hornet is a much more likely explanation.
If you genuinely suspect you have seen a yellow-legged hornet, do not attempt to catch it or interfere with a suspected nest. Take a photograph from a safe distance if possible and report the sighting through the official Asian Hornet Watch reporting system.
What about the giant Asian hornet?
This is where some of the confusion becomes unnecessarily alarming.
The yellow-legged hornet, Vespa velutina, has repeatedly been confused in newspaper and online coverage with the much larger giant Asian hornet, Vespa mandarinia.
They are completely different species.
The giant Asian hornet is not the invasive hornet species currently being monitored in Britain.
So if you see dramatic photographs online of an enormous hornet being described in connection with UK yellow-legged hornet sightings, check what species is actually being shown.
Our native European hornet is itself bigger than the yellow-legged hornet.
Correct identification matters far more than frightening headlines.
Where do European hornets nest?
European hornets naturally favour enclosed cavities.
Hollow trees are classic nesting sites, particularly splits and cavities inside mature trees, but they are by no means restricted to woodland.
We have found European hornet nests in roof spaces, workshops, outbuildings, wall voids and all sorts of other sheltered locations.
And they have a particular habit which surprises many people.
They will nest in chimneys.
This is something we see with European hornets which is far less typical of the common social wasps most householders are familiar with.
We also encounter overwintering queens in sheltered areas of buildings. The active colony itself does not survive the winter. Newly mated queens leave the old colony and find protected places in which to overwinter before starting a completely new colony the following spring.
Why does my hornet look black?
If you have found a very dark-looking hornet coming from a chimney, do not immediately assume it is an exotic species.
We have seen perfectly ordinary European hornets come out almost black because they are covered in soot.
Once the soot is taken into account, the normal European hornet colouring is underneath.
It is another reason identification should be based on several features rather than colour alone.
What does a European hornet nest look like?
Like other social wasps, European hornets make their nests from wood fibres which are chewed and mixed with saliva to create a paper-like material.
Inside are layers of comb containing the developing brood.
European hornet nests can become impressively large.
That does not necessarily mean there are vastly more hornets in the colony. The insects themselves are much larger than ordinary wasps, so the cells, comb and surrounding nest structure need more room.
Another feature we often see is that the lower part of the nest remains relatively open. Depending on where the nest has been built, that can sometimes assist with professional treatment.
When is European hornet season?
The colony begins much earlier than most customers become aware of it.
A queen that has survived the winter becomes active in spring and begins establishing a new nest. The first workers begin appearing as the colony develops through early summer.
In our experience, though, European hornet calls tend to come noticeably later than calls about ordinary wasp nests.
We normally begin receiving more enquiries from around the end of July and into early August. By then the colony has developed, the nest is considerably larger and there are enough workers moving around for people to start noticing them.
This is particularly obvious where hornets are flying around buildings or being attracted into houses at night.
The colony continues through late summer and produces new queens and males towards the end of the season.
The original queen, workers and males eventually die. Only newly mated queens survive the winter to begin the cycle again the following year.
What do European hornets eat?
European hornets are predators and play a useful part in the natural environment.
They hunt a wide range of insects including flies, moths, other wasps and honeybees. They also feed on sugary substances such as tree sap and ripe fruit.
The honeybee point is worth putting into perspective.
Yellow-legged hornets are rightly of concern because they can place sustained predation pressure on honeybee colonies.
But they are not the only wasp species that takes honeybees.
European hornets take honeybees as part of their natural prey, and common and German wasps can also cause problems around honeybee colonies, particularly later in the season.
So the difference is not simply that one species eats bees and the others do not.
It is the nature and potential scale of the predation from the invasive yellow-legged hornet that makes it a particular concern.
Are European hornets aggressive?
Their appearance suggests one thing. Their behaviour is usually quite another.
Despite their size, European hornets are generally quite docile when they are away from the nest.
That does not mean an active nest should be approached or disturbed.
Like other social wasps, European hornets will defend their colony if they believe it is under threat.
They can sting more than once, so give an active nest sensible space and do not attempt to treat it yourself.
Does every European hornet nest need treating?
No.
If a European hornet colony is in a hollow tree away from the house and is not causing anyone a problem, our advice may simply be to leave it alone.
They are native insects and useful predators. There is little point destroying a colony just because it exists.
Treatment is more appropriate where the nest location is creating a genuine problem, for example where hornets are repeatedly entering occupied rooms, nesting within a building or flying through areas regularly used by people.
Our starting point is to work out what is actually happening rather than automatically reaching for an insecticide.
How do Guardian Pest Control treat European hornets?
Where treatment is necessary, European hornet nests can normally be controlled using similar professional methods to other social wasp nests.
Depending on the location and construction of the nest, we may use a professional insecticidal dust or liquid insecticide.
Where a nest is at height, our technicians have an eight-metre extendable treatment pole system. Taking the working height of the technician into account, this allows us to reach many suitable nests at around 10 metres while working from ground level.
Access and safety are always assessed first.
If the colony is somewhere that cannot be treated safely, we will tell you rather than taking unnecessary risks.
European hornets in chimneys
Chimneys need a little more thought because seeing hornets entering the chimney does not necessarily tell you exactly where the nest is.
They may be using part of the flue system, or the nest may be within the larger chimney void.
We first need to understand how the chimney is constructed and where the hornets are actually active.
Where an ordinary nest treatment is not possible, we have specialist methods for treating suitable chimney infestations.
This is not something we recommend householders attempt themselves. An active hornet colony inside a chimney or enclosed void should be assessed before anything is disturbed.
I have found a European hornet. What should I do?
If it is simply flying around outside, there may be nothing you need to do.
If one has come indoors at night, the chances are it has been attracted by your lights rather than deliberately trying to get into your home.
Get in touch if:
- You are seeing them repeatedly
- You can see hornets regularly entering the same part of a building
- There is a nest somewhere people regularly pass
- You are not sure whether you are looking at a European hornet or a yellow-legged hornet
We will help you work out what you have got and the most sensible next step.
European hornet control across Somerset and Devon
Guardian Pest Control provides professional European hornet identification and nest treatment across Somerset and Devon.
If a nest does not need treating, we will tell you. If it does, we will explain the options and how we can deal with it safely.
