FaunaHub

Spider

ArachnidPredatorInvertebrate

A European garden spider sitting at the centre of its orb web.

European garden spider (Araneus diadematus) on its web.

Image: Charles J. Sharp, CC BY-SA 3.0, via Wikimedia Commons.

Overview

Spiders are arachnids in the order Araneae — they are not insects. All spiders have eight legs, two body sections, and the ability to produce silk, and nearly all possess venom used to subdue prey. There are tens of thousands of described species worldwide. This page is a group-level overview; a garden orb-weaver (Araneus diadematus) is shown as a familiar reference. Spiders are important predators of insects in almost every land habitat.

Habitat & Range

Spiders live on every continent except Antarctica and in nearly every land habitat — forests, grasslands, deserts, wetlands, caves, gardens, and inside buildings. Some build webs in vegetation or structures, while others live on the ground, in burrows, or among leaf litter. A few even live at the water's edge. Habitat and lifestyle vary enormously between species.

Diet

Spiders are predators, feeding mostly on insects and other small invertebrates. Web-building spiders snare prey in silk and many inject digestive fluids to feed, while hunting spiders such as wolf spiders and jumping spiders actively chase or ambush prey without a web. By consuming large numbers of insects, spiders play an important role in controlling invertebrate populations. Diet varies by species.

Behavior

Spiders use silk in many ways — building webs, wrapping prey, lining burrows, making egg sacs, and "ballooning" on strands to disperse on the wind. Web-builders and active hunters represent two broad lifestyles within the group. Most spiders are solitary, and many are most active at night. Courtship can be elaborate, especially in visual hunters such as jumping spiders. Behaviour varies widely across the order.

Human Interaction & Conservation

Spiders are beneficial predators that help control insect numbers in gardens, farms, and homes. The great majority are harmless to people; only a small number of species have venom of medical significance, and bites are uncommon. Wildlife and health sources advise not handling spiders you cannot identify and seeking medical advice if a bite causes a strong reaction. Most spiders are common, and conservation concern applies mainly to specialised species.

Appearance & Recognition

Spiders have two main body regions — a combined head-and-thorax (cephalothorax) and an abdomen — joined by a narrow stalk, plus eight legs and (in most species) several pairs of eyes. At the rear are spinnerets that produce silk, and at the front are fangs. Having eight legs and two body sections distinguishes spiders from insects, which have six legs and three body sections. Size, colour, and eye arrangement vary greatly between families.

Similar Animals

Spiders are arachnids, related to scorpions, mites, ticks, and harvestmen, rather than to insects. They are often grouped with insects in everyday language, but the bee, butterfly, and ant covered on FaunaHub are true insects with six legs, while spiders have eight. Harvestmen ("daddy longlegs") look spider-like but are a separate arachnid group.

More photos of the spider

A crowned orb-weaver spider on its web with dewdrops.

A crowned orb-weaver spider.

Image: Ryan Hodnett, CC BY-SA 4.0, via Wikimedia Commons.

Frequently Asked Questions — Spider

Are spiders insects?
No. Spiders are arachnids, not insects. They have eight legs and two body sections, while insects have six legs and three body sections. Spiders are more closely related to scorpions and mites than to bees or ants.
Are most spiders dangerous to people?
No. The vast majority of spiders are harmless to humans, and bites are uncommon. Only a small number of species have venom of medical significance. As a precaution, avoid handling spiders you cannot identify and seek medical advice if a bite causes a strong reaction.
How do spiders make webs?
Spiders produce silk from glands connected to spinnerets at the rear of the abdomen. Web-building species use this silk to construct snares of various designs, but not all spiders build webs — many are active hunters that use silk mainly for shelters, draglines, or egg sacs.

Sources and further reading

Authoritative wildlife references used for general educational context. Conservation status should always be verified against current IUCN Red List data. External links open in a new tab.