Spider web

\nA spider web is a device built by a spider out of proteinaceous spider silk extruded from its spinnerets. The most familiar spider webs are those used for catching flying insects, but some are used to ensnare small vertebrates, and others only provide shelter. Webs typically contain multiple types of strands, including sticky and non-sticky ones. Some of these strands are stronger than steel strands of the same thickness; the microstructure of this material is under investigation for potential applications in industry. In spiders, there are several glands located at the spider's abdomen which produce the silken thread. Every gland produces a thread for a special purpose with several different glands currently identified, although spiders possess a few of these glands, never all seven at once. Glands:\n*Glandula Aggregata produces the sticky material for the threads.\n*Glandula Ampulleceae major and minor is used for the silk of the walking thread. \n*Glandula Pyriformes is used for the production of the attaching threads.\n*Glandula Aciniformes produces threads for the encapsulation of prey.\n*Glandula Tubiliformes produces thread for cocoons.\n*Glandula Coronatae is used for the production of the adhesive threads. Normally a spider has three pairs of spinners. But there are spiders with just one pair or as many as four pairs of spinners, with each spinner having its own function.

Sources

• Ed Nieuwenhuys; March 2002; The Spider Web and Thread;