A spider web, spiderweb, spider's web or cobweb (from the obsolete word coppe, meaning "spider", sometimes with the connotation of being a dusty, abandoned web) is a device built by a spider out of proteinaceous spider silk extruded from its spinnerets.

Insects can get trapped in spider webs, providing nutrition to the spider; however, not all spiders build webs to catch prey, and some do not build webs at all.

Types of spider web

There are a few types of spider webs found in the wild, and many spiders are classified by the webs they weave. Different types of spider webs include:

• Spiral orb webs, associated primarily with the family Araneidae, as well as Tetragnathidae and Uloboridae
• Tangle webs or cobwebs, associated with the family Theridiidae
• Funnel webs, with associations divided into primitive and modern
• Tubular webs, which run up the bases of trees or along the ground
• Sheet webs
• Dome or tent webs

Several different types of silk may be used in web construction, including a "sticky" capture silk and "fluffy" capture silk, depending on the type of spider. Webs may be in a vertical plane (most orb webs), a horizontal plane (sheet webs), or at any angle in between. Most commonly found in the sheet-web spider families, some webs will have loose, irregular tangles of silk above them. These tangled obstacle courses serve to disorient and knock down flying insects, making them more vulnerable to being trapped on the web below. They may also help to protect the spider from predators such as birds and wasps.

Formation

Spiders have several spinneret glands located at their abdomen, which produce the silken thread. Each gland produces a thread for a special purpose. Seven different gland types have currently been identified, although each species of spider possesses only a few of these types, never all seven at once.

Normally a spider has three pairs of spinnerets, but there are spiders with just one pair or as many as four pairs of spinnerets, with each spinneret having its own function.

During the process of making a web, the spider will use its own body for measurements, a very practical and ergonomic design feature of any web. This will allow the spider to move quickly around its own web with very few faults.

It will start with the most difficult part of construction, the first thread. The spider effectively uses the wind to carry its initial adhesive thread. With some luck, the silk is released from its spinners and carried by the wind to a suitable adherable surface. When it sticks to a surface, the spider will carefully walk over the thread and strengthen it with a second thread. This process is repeated until the primary thread is strong enough to support the rest of the netting.