Arachnids and their role

In short: Arachnids such as spiders, scorpions, and ticks have eight legs and belong to the arthropods, not the insects. Many play important roles as predators of pest insects.

In more detail: Unlike insects with six legs and three body segments, arachnids have eight legs and usually two body segments.

In detail

• Body structure: The forebody (cephalothorax) and hindbody (abdomen) are the two main sections of most arachnids.
• Spider webs: Not all spiders build webs; some hunt actively or lie in wait for prey.
• Venom: Most spiders have venom for hunting prey, but only very few species are dangerous to humans.
• Scorpions: Use the venomous stinger on their tail for defence and catching prey.
• Ticks: As parasites, they can transmit pathogens such as the bacteria causing Lyme disease.
• Ecological importance: Spiders regulate insect populations and are an important part of many food chains.
• Common misconceptions: Most spider species are harmless to humans, despite widespread fear of them (insekten-und-bestaeuber, nahrungskette-und-oekosystem).