Spiders belong to the class of arachnids like the scorpions and mites. Unlike the insects, they have eight legs, eight eyes and in most cases, no wings and only two, not three, parts to their bodies.
Spiders are found everywhere in every kind of climate. They manufacture a silk with which they spin this web.
At the tip of its abdomen, there are spinning organs having holes. The silk is forced out through these holes, which becomes solid as soon as it comes in contact with air. Spiders are meat eaters, feed on insects and other spiders, which get trapped in their web.
Below Spiders info from Wikipedia (Read More):-
Spiders (order Araneae) are air-breathing chelicerate arthropods that have eight legs, and chelicerae modified into fangs that inject venom. They are the largest order of arachnids and rank seventh in total species diversity among all other groups of organisms[1]. Spiders are found world-wide on every continent except for Antarctica, and have become established in nearly every ecological niche with the exception of air and sea colonization. As of 2008, approximately 40,000 spider species, and 109 families have been recorded by taxonomists.[2] However, there has been confusion within the scientific community as to how all these genera should be classified, as evidenced by the over 20 different classifications that have been proposed since 1900.
http://en.wikipedia.org/wiki/Spider
