Spider anatomy

The anatomy that gives a spider away

Two body parts, eight legs, up to eight eyes and silk on demand. Learn the blueprint and identification stops being guesswork.

Two body sections

A spider's body splits into the cephalothorax (head + thorax) and the abdomen, joined by a narrow waist. Unlike insects, spiders have no wings and no antennae.

  • Cephalothorax carries the eyes, fangs, pedipalps and all eight legs
  • Abdomen houses the internal organs and silk glands
  • Relative size of the two parts is a top identification signal

Eight legs, seven segments

Each leg has seven segments — coxa, trochanter, femur, patella, tibia, metatarsus and tarsus — and does far more than walk.

  • Legs detect vibration, capture prey and aid climbing
  • Spiders have no muscles to extend legs — they use hydraulic pressure
  • Length, thickness and stance separate hunters from web-builders

Up to eight eyes

Most spiders have eight eyes, but ability varies enormously. Their number and arrangement is a key feature for AI identification.

  • Jumping spiders see colour and fine detail with two huge eyes
  • Web-builders rely mostly on sensing vibration
  • A brown recluse breaks the rule with six eyes in three pairs

Markings that matter

Body markings are often the fastest way to flag a high-risk species — and the model weighs them heavily.

  • A red hourglass underneath points to a black widow
  • A violin shape on the back hints at a brown recluse
  • Banded legs, spots and a cross are common, telling patterns
What the AI looks at

The five signals that give a spider away

Tap a signal to see what the model reads. Together, these features narrow thousands of species to a confident shortlist.

Body shape
Web types

Read the web, narrow the spider

Not every spider builds a web — but the ones that do leave a signature you can recognise at a glance.

Orb web

The classic circular wheel of garden spiders — sticky spokes radiating from a hub.

Garden & golden orb-weavers

Funnel web

A flat sheet leading to a tube-shaped retreat at ground level where the spider waits.

Funnel weavers, hobo spider

Sheet web

Dense, flat horizontal layers, sometimes with a tangle of threads above to knock prey down.

Sheet weavers

Cobweb

An irregular three-dimensional tangle built into corners — messy but highly effective.

House spiders, widows