Spiders - why do spiders spin webs?
Quatr.us answers questions

Why do spiders spin webs?

A fossil spider

Spiders evolved from annelid worms beginning about 540 million years ago. They were among the first land creatures with more than one cell.

Orb web
An orb web

By about 300 million years ago, spiders evolved silk and spinnerets and could spin webs. They probably ate other early arthropods, and lived on the ground among the big ferns and mosses that grew all over the earth at this time.

At about the same time, the first bigger land animals began to come out of the water: frogs and salamanders. These ate spiders.

The earliest evidence of an orb web, the round kind that is the most normal kind of spider web, comes from one that was preserved in amber about 110 million years ago, but spiders were probably making these webs as early as 135 million years ago. That's because flying insects like grasshoppers and bees were evolving at this time, and so the spiders evolved webs to catch them. At the same time, birds also evolved that could eat the bees and grasshoppers - and also eat spiders.

Bibliography and further reading:

Quatr.us home

Professor Carr

Karen Eva Carr, PhD.
Assoc. Professor Emerita, History
Portland State University

Professor Carr holds a B.A. with high honors from Cornell University in classics and archaeology, and her M.A. and PhD. from the University of Michigan in Classical Art and Archaeology. She has excavated in Scotland, Cyprus, Greece, Israel, and Tunisia, and she has been teaching history to university students for a very long time.

Professor Carr's PSU page

Help support Quatr.us!

Quatr.us (formerly "History for Kids") is entirely supported by your generous donations and by our sponsors. Most donors give about $10. Can you give $10 today to keep this site running? Or give $50 to sponsor a page?

For the US election, check out Quatr.us' page on the Constitution. From the Revolution on, people have fought for the right to vote. In the 1800s, Andrew Jackson got poor white men the vote; the Civil War and Lincoln brought the vote to African-American men. In the 1900s, women got the vote, and Martin Luther King Jr. fought to force white people to actually let black people vote.