DID YOU KNOW? 1. There are about 35,000 known spider species, although scientists estimate that there may be about 180,000 species in the world. About 2,000 of these inhabit the U.S., but only a few of those spider species build elaborate webs. 2. Spider webs are built from silk, which is produced within the body of the spider and pulled out of two openings, or spinnerets, with the spiders hind legs. 3. All spiders have two claws on their feet, but web-spinning spiders have three. They are used not only to pull the silk, but also to grip and release the web’s threads and provide traction as they move along the web. 4. Spiders spin two kinds of silk: Sticky silk, or viscid silk. Used to capture prey, this stretchy, wet silk makes up the spiraling threads of the web. Non-sticky silk, or dragline silk. Used to strengthen and the provide structural support of the web onto which the viscid silk is woven, this silk is stiff and dry. To keep from getting caught in their own webs, spiders avoid walking on the sticky silk. 5. The strength of a web is dependent on the strength of the spun silk, but also on the webs design itself. 6. A web is constructed so that if any part of it is disturb, a reaction is felt across the entire web, alerting the spider to its trapped and struggling insect food. 7. In addition, it is constructed so that failure in one area will not cause the entire web to fail, but will forfeit only the failing section. 8. Spiders rebuild their webs by eating the silk then recycling it to make new webs. 9. Webs have multiple purposes, but the most important one is to trap insects for food. 10. Webs are also used: to travel, or balloon, from one place to another. as protection at the entrances of their dwellings. to encase egg sacs. 11. It is the female spider who builds the webs. 12. Spider webs can prove to be useful indicators of environmental chemistry. For example, researchers were able to deduce levels of lead and zinc in limestone arches in caves in Australia based on analysis of water-soluble ions in spiderwebs at the sites.
Posted on: Tue, 19 Aug 2014 20:00:42 +0000
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