The hornet (Latin Vespa crabro) is the largest species of wasp native to us and can grow up to 35 millimeters long. The strikingly colored insect belongs to the wasp family and forms comparatively small colonies. Hornets hunt other insects, which they also like to do at night.
Are hornets nocturnal?
Hornets are active both during the day and at night, especially at dusk in summer between 7 p.m. and 11 p.m. The nocturnal activity results from the need to feed their larvae at night and to take advantage of the reduced threat from enemies.
- Hornets are particularly active between 7 p.m. and 11 p.m., but occasionally fly all night long
- The reasons for this are probably that hornet larvae are also fed at night and there are fewer enemies around at night
- Hornets, like other insects, are attracted to light sources, which is why they can enter the apartment through open windows at night
Are hornets nocturnal?
In fact, hornets are not only out and about during the day, but also at dusk and at night. According to a study in which the movement patterns of the animals were recorded using a sensor and a camera, the giant wasps fly more frequently in the summer dusk between 7 p.m. and 11 p.m. After that, flight activity slows down somewhat, so that only a few animals are on the move late at night and into the early hours of the morning - but nocturnal activities do not come to a complete standstill.
Hornets are therefore active both during the day and at night, which in turn distinguishes them from their relatives - the various species of wasps - as well as from bees and bumblebees. These insects fly exclusively during the day and spend the night in their nests.
Why do hornets fly at night?
There are several reasons for these nighttime activities. One is that the hornet larvae have a great appetite for protein-rich food and are therefore fed at night - although not as often as during the day, but there are no real periods of rest in the hornet's nest. A hornet colony consumes around half a kilogram of insects per day in its late summer peak phase! And since the state is not particularly large with an average of 400 to 700 animals, there is always hunting.
Furthermore, the danger from enemies at night - hornets are coveted prey for many birds - is lower than during the day, and food competitors (again birds) are also inactive at this time. There are lots of nocturnal insects, such as the moths mentioned above.
Light sources attract hornets
Hornets are attracted to light sources
Moths and other nocturnal insects are magically attracted to light. This also applies to hornets flying at night, which always orientate themselves on existing light sources and can therefore get lost in the apartment in summer. Like all nocturnal insects, hornets orientate themselves at dusk or darkness at the brightest point in nature, the moon. This appears to be motionless in the sky and is therefore very suitable as a fixed point: the insects always maintain an angle of around 40 degrees to the moon and thus manage to fly straight ahead. The animals don't see particularly well at night - in contrast to during the day.
However, if an artificial light suddenly appears - such as a lamp or lantern - the insect uses this as a reference point and flies towards the light. Unfortunately, such light sources are much closer than the distant celestial body and are therefore not suitable for correctly determining the flight path. However, the hornet doesn't know this and ends up in your apartment in no time.
Hornet flies into the apartment, what to do?
Now the hornet is suddenly buzzing around your apartment and can't find its way out. Please don't grab your slippers or a newspaper to kill the animal - firstly, hornets are rare and secondly, they are protected. The animals may not be killed or captured, as stipulated by the Federal Nature Conservation Act (BNatSchG). For the same reason, aid measures such as insect spray or hair spray are also prohibited, especially since both are a very painful way of killing the animals. But don't worry, you can still lure the hornet back outside with a simple trick:
- Open the room window wide.
- Place a light source (such as a candle) on the outside window sill.
- If the room is adjacent to a balcony, you can also put the light here.
- Turn off the light in the room.
- Wait.
After a while, the hornet will orient itself towards the new light source and fly outside again. Now close the window and only then turn the light back on. Alternatively - and if you're feeling really brave - just wait until the hornet settles on an easily accessible surface. Now quickly put a glass over the animal and push a piece of cardboard over the opening. Take the jar with the hornet outside and release the insect there.
If a hornet gets lost in the apartment, keep calm
How to keep hornets out of your home
However, you can also reliably prevent the animals from wandering around by closing the window openings with insect screens (€15.00 on Amazon). This also has the advantage that you can turn on the light in summer even when the window is open and you don't have to worry about an invasion by nocturnal insects. Hornets also don't like the smell of certain plants and avoid them. So place the potted plants listed below on the windowsill:
- Lemon balm
- Lavender
- Basil
- Peppermint
Hornets also don't particularly like tomatoes and frankincense, but both species are usually too big to keep on the windowsill. But they are well suited for growing in pots on the balcony or terrace.
Excursus
Are hornets dangerous?
Do you also know the old saying “Three hornet stings kill a person, seven kill a horse”? This is an old wives' tale with no basis in truth. In fact, hornets are quite peaceful animals and will leave you alone as long as you don't make any hectic, flailing movements around them or even attack them. Hornets are neither interested in humans nor in their food (in contrast to common wasps). The sting is no more dangerous than that of a wasp or bee; only those allergic to wasp venom need to be careful. Since wasp and hornet venom are chemically very similar, reactions can occur.
When do hornets fly?
“Hornets scare many people. But this is completely unnecessary, as these animals are not very aggressive and tend to flee.”
Depending on the weather, the hornet year begins between April and May, when the queens emerge from their winter quarters and start looking for a suitable nesting place. The first workers do not fly out until June, as they first have to hatch and develop into an adult. The hornet population finally experiences its peak phase in late summer, when around 400 to 700 animals populate the nest and there is hectic activity there.
From around the end of August until September, the male animals, called drones, as well as the newly hatched young queens fly out for their nuptial flight. In October, but no later than November, the last workers, the old queen and the drones die. During the day, hornets have two peak flight phases in which the animals are particularly busy: the first phase is at midday, the second at dusk until the early hours of the night.
This very nice article by a beekeeper explains how a hornet's life goes and provides further interesting information.
Hornissen - Beobachtungen, Angriff und Überraschung
Do hornets actually sleep?
Given the fact that hornets are on the move practically day and night during the summer months, the question arises as to whether the animals never sleep? In fact, it seems that the giant wasps do not need sleep or any other periods of rest. In any case, both the workers and the drones don't live particularly long: the lifespan of these animals is a maximum of four weeks, while their queen is the only one that can live around a year. Of course, this short period of time must be utilized, which is why sleep is superfluous and simply takes up time. Only in the very early hours of the morning do there sometimes be very brief standstills in the nest, where almost all the animals stop for about half a minute to a minute and don't even move their antennae.
What do hornets do in winter?
Almost the entire hornet colony dies off in the fall. All that remains are the young queens that hatched in late summer or autumn and look for suitable winter quarters after mating. The animals like to burrow into the ground, but also use piles of wood or cavities. Many a hornet has overwintered in a pile of firewood and then woke up early in the living room when the wood was being carried to the fireplace.
Excursus
What do hornets do in cooler weather?
Basically, hornets are more active on warm and sunny days, while flight movements decrease significantly on cooler days. The reason for this is the fact that both the workers and the drones “heat” the nest on such days. To do this, the animals crowd together in the center and generate heat with tiny movements of their wings. Being so busy, they naturally have less time to go hunting outside.
Frequently asked questions
There is a hornet's nest outside my window. How do I get rid of this?
First of all: You are not allowed to remove the nest yourself, nor do you smoke it out or kill the animals in any other way. Hornets are protected, which is why you need a good reason and official permission to remove the nest. You can usually apply for this from the local nature conservation authority in your community. In addition, the nest should always be relocated by a professional.
Hornet, wasp or bee: How do I distinguish between the individual species?
Hornets are the largest wasp species in Central Europe and are also strikingly yellow-reddish in color. These two characteristics alone make it easy to distinguish them from their relatives, the wasps. Bees, on the other hand, are even smaller and also have a more brownish color.
How can I get rid of hornets?
You must not kill, capture or damage hornets' nests. However, you can try to prevent the queen from building a nest in the spring or use gentle means to drive the animals away. Some essential scents are very suitable for this purpose, for example clove oil, lavender or lemon balm oil.
Tip
In the spring, pay more attention to whether you see a queen hornet flying in and out somewhere. If so, she builds her nest there. At this point, close all entry holes, of course only when the animal is outside again.
