Spiders belong to a class known as Arachnida and more commonly known as the
arachnids. They share the class with other species including scorpions,
harvestmen, ticks and mites. Spider are mistakenly called insects (class
Insecta), however the main difference between the two are spiders have
eight legs whilst insect have six. Both spiders and insects belong to the
largest group of animals on Earth, the arthropods.
Another distinguishing feature of Arachnids are they have no antennae and no
wings, with most being carnivorous, feeding on pre-digested bodies of insects or
other small animals and birds. Some are parasites, whilst many are venomous,
secreting poison from specialised glands.