spiderweb

A spiderweb, or spider web, is a silk structure produced by spiders from silk glands and expelled through their spinnerets. The silk is a protein-based polymer with varying strength, elasticity, and stickiness, allowing a range of web designs and functions.

Most webs function to capture prey, though they can also provide shelter and reproduction sites. Orb webs are wheel-shaped with radiating spokes and a spiraling capture silk. Sheet webs form horizontal layers or flat sheets that intercept flying insects, sometimes with a tangled or funnel-like region. Cobwebs are irregular, three-dimensionally tangled masses that often occur in corners or sheltered places. Some spiders, including tarantulas, rely less on webs for prey capture and may use silk primarily for protection or egg sacs.

Spiders construct webs by secreting silk from several spinnerets and pulling strands to form frames, radii, and capture spirals. Sticky viscid silk droplets coat parts of the capture spiral to enhance prey adhesion, while non-sticky silk provides structural support. Webs are delicate and are frequently repaired or rebuilt after damage from weather, prey impacts, or aging.

Beyond prey capture, silk lines serve as anchors, retreat entrances, and egg-sacs. Silk may be used for dispersal during early life stages (ballooning). Web architecture varies with species, habitat, and prey availability, contributing to ecological interactions and insect population dynamics.

The ecological and biological study of spider webs informs our understanding of biomechanics, evolution, and biodiversity, and spider silk has attracted interest in materials science due to its unique properties.