Spiders' silk is produced in special silk glands and distributed by the spinnerets. A variety of glands produce different kinds of silk for specific parts of the web, for binding prey and for the egg cocoon. Parts of the glands produce the gum for snare lines. The spinnerets have many minute spinning tubes at their tips. Each thread consists of many filaments fused together.

The spinneret is an organ used used by spiders and some insect larvae to spin silk. Spinnerets are nozzle-like organs usually situated on the underside of the abdomen, towards the rear. Spiders may have between 2 and 8 spinnerets, depending on the species, and each spinneret can move independently or in concert with others.