Why is an spider not an insect?

Answer 1

They are aracnids which means that they have eight legs instead of six. Insects have an exoskeleton, a three-part body (head, thorax, and abdomen), three pairs of jointed legs, compound eyes, and two antennae.

Spiders have eight legs, and soft bodies.

Answer 2

Because all insects have six legs, spiders have eight legs.

Insects have three parts to their body spiders have two.

Insects have antennae spiders do not.