A spider has eight legs and two body parts, while an insect has three body parts. Spiders are arachnids, not insects, and most spiders have eight eyes, though some have fewer. Most spiders are harmless to people, and spiders very rarely bite people. Do not touch a wild spider, and if you see one, tell a grown-up.

Every kind of spider makes silk with spinnerets. Spider silk is very light but also extremely strong and flexible. Many spiders catch flies and other insects in their webs. A spider web has sticky threads and nonstick threads, and the spider knows which threads are safe to walk on. An orb web has radial threads that make the frame and a spiral thread that catches prey. Orb-weaving spiders often eat their old silk and reuse it.

Not every spider builds a web, and some hunt for prey or wait for it. Wolf spiders are hunting spiders, and they do not build webs to catch prey. Jumping spiders hunt in the daytime and have very good eyesight, and they can see more colors than people can.

Most spiders eat insects, and spiders in gardens eat many kinds of insects, including pests. Spiders use venom to paralyze the small animals they catch. After catching an insect, a spider wraps it in silk. Spiders cannot chew solid food, so they put digestive fluids into their prey, and a spider's mouth is shaped like a tiny drinking straw that sucks rather than chews. Many animals eat spiders, including birds.

Words to know

• spinnerets: silk makers
• radial: like spokes
• spiral: winding curve
• arachnids: spider group