October 10, 2024, 11:34 am | Read time: 4 minutes
Very few people like to see spiders sitting in the corner of their room. However, the animals are often drawn into houses and apartments, especially in the fall. myHOMEBOOK asked a spider expert why this is the case.
Around 1000 different species of spider live in Germany. But they don’t exactly have a good image. Not only do they look unusual with up to eight eyes, skinny legs, and fast movements, but they also spin sticky webs in the corners of the room. Only at a second or third glance do you notice how artfully the thin threads have been arranged. But why do spiders mainly come into our home in the fall?
Overview
How do spiders react to the fall?
If you believe an old farmer’s saying, people can even draw conclusions about the weather from the behavior of spiders in autumn. It says: “When the spiders crawl in September, they can already smell winter.”
Prof. Dr. Wolfgang Nentwig from the Institute of Ecology and Evolution at the University of Bern doesn’t think much of the farmer’s rule: “Basically, most spider species don’t care about the approach of winter, as they die with colder days anyway,” explains the arachnologist. “They usually hibernate in the egg stage; only comparatively few species hibernate as juveniles or even adults. They react to the drop in temperature towards the end of the year, look for sheltered places, and switch their metabolism to cold protection.”
What is the reason for the increased activity?
Dr. Jason Dunlop, spider researcher and curator at the Museum für Naturkunde Berlin, is also skeptical about the farmer’s rule. At the very least, there is no evidence that arachnids are sensitive to the weather. However, Dunlop has a completely different explanation: “Spiders are indeed often found in living spaces in September, especially the conspicuously large house spider,” explains the scientist. “But the background to this is that for many spiders, the mating season takes place in the fall. The males leave their hiding places and run around in search of females.”
Can spiders really predict the weather?
There are also species that are active all year round. “Finding moving spiders (“crawling”) in September, therefore, has nothing to do with them ‘smelling’ winter and possibly preparing for a possible hibernation.” Spiders are, therefore, unable to predict the onset of winter, as the saying goes, but they do have some mature sensory organs with which they perceive their environment. What’s more, these have also been quite well studied, says Nentwig. Spiders can therefore:
- detect movement in the air and vibration of the ground
- smell or taste odorous substances on surfaces
- measure the temperature, humidity, air pressure, and CO2 content of the air
- see (black and white, some in color, also UV)
This allows spiders to determine, for example, whether it is too wet at the moment to build a web. They then wait a few hours or a day to do so. However, this has nothing to do with the farmer’s rule that ascribes weather sensitivity to spiders. The spider researcher is therefore puzzled as to how the animals are supposed to measure or recognize the future weather according to the farmer’s rule. They simply lack the necessary sensory organs for this.
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How can you prevent spiders from getting into your home?
The weather in autumn and the behavior of spiders cannot be changed. Nevertheless, there are various ways to prevent the small animals from entering your home. For example, a fly screen on the windows can help. However, spiders can also be driven away with the right smells, as confirmed by a study. Lavender, vinegar, chestnut, peppermint, lemon, and eucalyptus – the eight-legged friends don’t like these scents and stay away.