The web of a spider provides rigidity and strength enough to trap its food. The web is both obtained with minimal material, all of which is manufactured by the spider itself. The threads do not simply cross at intersections but are ‘soldered’ together with fine threads.
Every spider is a virtual genius working like as an architect, weaver, chemist, structural engineer, and information scientist.
In fact, compared to human abilities spiders have virtual superpowers. How does the spider know it needs to hunt and trap its meals? How does the spider learn how to build its web?
Textbook answers are the ultra-simple “answer”: “instinct”.
Instinct as the answer echoes hallow because the answer does not define how instinct occurs or how it emerged. The answer merely describes the observable end result. But the questions remain: How does instinct work? Where does it reside biochemically? When did such skills and abilities emerge? As an example: How could the lowly spider know how to do such complex tasks as weaving a geometric web, intended for the purpose of trapping and capturing food?
All without so much as a single year of college? Wow!
http://www.bbc.co.uk/guides/zc472hv