While many people associate spiders with intricate silken traps, the notion that all spiders spin webs is a common misconception. Many spider species use webs for prey capture, but others employ different hunting strategies. All spiders, however, produce silk, a versatile material essential for various aspects of their lives beyond just ensnaring food.
Spiders That Spin Webs
Many spiders construct diverse silk structures to capture meals. Orb-weaver spiders build classic, wheel-shaped webs to intercept flying insects. These webs feature strong, non-sticky radial lines that provide structural support and sticky spiral threads that ensnare prey. The spider often waits at the web’s center or a nearby retreat, sensing vibrations from a trapped insect before quickly immobilizing it with a venomous bite and wrapping it in silk.
Other web-spinning spiders create different silk traps adapted to their environments and prey. Funnel-web spiders construct sheet-like webs that lead into a funnel-shaped retreat, often nestled in rocks or dense vegetation. They hide within the funnel, rushing out to ambush insects that wander onto the sheet. Tangle webs, or cobwebs, are irregular, three-dimensional structures built by spiders like the common house spider. These seemingly haphazard webs are effective at entangling prey and are frequently found in corners and crevices.
Spiders That Don’t Spin Webs
Many spider species do not rely on webs for hunting, instead employing active and ambush predation. Wolf spiders are active hunters, using their eyesight and speed to stalk and pounce on prey. They do not build webs for prey capture, instead chasing down insects like crickets and beetles, or even other smaller spiders. Wolf spiders may also use ambush tactics, waiting patiently for prey to come within striking distance before attacking.
Jumping spiders are highly visual hunters known for their agility and calculated leaps. These spiders possess exceptional binocular vision, allowing them to track prey movements with precision. They actively stalk their targets, often repositioning themselves and planning their approach before making a powerful jump to capture their meal. Crab spiders are masters of ambush, camouflaging themselves on flowers or leaves to wait for insects. They use their long, powerful front legs to quickly grab and paralyze prey, such as bees, flies, or butterflies, once it comes within reach.
More Than Just Hunting: Other Uses for Silk
While not all spiders build webs for hunting, all spiders produce silk, a protein-based fiber generated from specialized glands called spinnerets. Spiders can produce up to seven different types of silk, each with unique properties and functions. One common use is for a dragline, a safety line spiders trail behind them, providing escape or a way to return. This dragline silk is strong and elastic.
Spider silk is also used for reproduction, as females construct silk egg sacs to protect their eggs. These sacs can vary in shape and size, containing dozens to hundreds of eggs depending on the species. Some spiders also use silk to build shelters or burrows, creating a safe retreat. Young spiders, and sometimes adults, use “ballooning” by releasing long silk threads to catch the wind, dispersing over long distances. This dispersal method helps spiderlings avoid competition and find new habitats.