>Class: Arachnids
Size: 0.4 to 10cm
Weight: max. 130g
Age: 1 to 15 years
Appearance: Eight-legged, different colours possible Colours possible (black, brown, yellow, red)
Sexual dimorphism: Yes
Feeding type: Insectivore (insectivorous)
Food: Ants, flies, beetles, ladybirds, mosquitoes, spiders
Distribution: Worldwide, 45’000 species
Sleep-wake rhythm: Diurnal or nocturnal
Habitat: Forests, meadows
Natural enemies: Amphibians, reptiles, birds
Sexual maturity: Species-specific
Mating season: June to October
Social behaviour: Solitary
Threatened with extinction: No

• Spiders always have eight legs.
• Currently, about 45’000 spider species are known and more than 100 new ones are added every year.
• So far, the exact cause of spider fear is still unclear. Observational learning seems to play an important role. Indigenous peoples from Indonesia or Brazil are not afraid of spiders, despite the fact that there are far more poisonous species living there.
• The smallest spider in the world can grow up to 4mm long (Patu digua), the largest over 10cm long (Bird spider).
• The size of the spider does not explain its toxicity. The tarantula’s venom, for example, is too weak to kill a human.
• Spiders have tiny organs, including the brain and heart.
• Spider glands are found in the abdomen of spiders and can be used to make spider silk. Spider silk is one of nature’s most stable materials.
• The spider’s web consists of sticky and non-sticky spider silk. Only the spider itself knows which threads it can move on without getting stuck.
• Black widows sometimes eat the male after mating.
• Spiders hunt and feed mainly on insects and arthropods. They usually kill them first with their jaw claws and then dissolve them by injecting an enzyme-containing digestive juice before consuming them.
• In the course of evolution, spiders have developed different hunting techniques: weaving spider webs (weaver spider), jumping on prey (bark spider), digging holes (trapdoor spider), hunting in water (water spiders) or spitting venom at prey (spitting spider).
• Spiders are indispensable for many ecosystems.
• Besides active hunting, there are supplements in their diet. Almost all spiders eat freshly killed animals and are therefore also scavengers. However, there is also evidence that a non-negligible part of the spider’s diet is pollen, which is ingested together with old spider threads.
• In the societies of western industrialised countries, there is an irrational aversion to this group of animals, which can even lead to pathological arachnophobia, although in these countries spiders that can be dangerous to humans exist only in Australia. Less than 12 of the approximately 40’000 species are dangerous to humans, but rarely with serious consequences. On the other hand, in societies where dangerous spiders are more common in the environment, they are tolerated, eaten as delicacies and even worshipped as gods.
• Most spider venom is not used to kill, but to stun and preserve. Only through a killing bite or consumption is the prey killed.