Spider webs or cobwebs are commonly found throughout homes in the Western and Northwestern U.S. states. Spider webs are created by spiders out of silk that is extruded from spinnerets to help catch prey. Catching prey is not the only reason spiders spin webs. Some spiders, like the brown recluse, use their web to help protect their eggs.
Different types of spider webs
Where do spiders build their webs?
What are spider webs made out of?
Cobwebs and spider webs may seem similar, but they have distinct differences. A spider web is an active structure built by a spider to catch prey. In contrast, cobwebs are abandoned or old spider webs that have collected dust and debris over time. They are often associated with neglected corners of homes, basements, and attics. Many cobwebs are left behind by comb-footed spiders (Theridiidae family), including black widows, whose irregular, messy webs can turn into cobwebs once the spider moves on or dies.
Various species of spiders are classified based on the types of webs they weave. Different types of spider webs include:
Spiral orb webs are the most common spider web. This web design is associated with the family Araneidae and species include orange garden orb weaving spiders, banded orb weaving spiders, bolas spiders and silk spiders, just to name a few. This web looks like a wheel with spokes. Orb-weaving spiders and their webs are typically found outdoors.
Tangled webs or cobwebs are associated with the family Theridiidae, and common species include the house spider and ogre-faced stick spider. Tangled webs lack symmetry and are jumbles of threads typically attached to a support system like the corner of a ceiling. Cobwebs have the same lack of structure as tangled webs and often collect dirt and debris.
Sheet webs are flat sheets of silk between blades of grass or branches. When creating sheet webs, spiders spin a net of criss-crossed threads above the sheet. Flies end up hitting the net and bouncing into the sheet web. If the sheet web is damaged, the spider quickly patches up any holes or tares. Sheet webs are associated with the family Linyphiidae, and species include the bowl and doily spider and the platform spider.
Funnel webs are large, flat horizontal webs with openings at both ends so the spider can escape. Funnel-web spiders can feel the vibration of prey once present and bite it so it can bring it back to the funnel web. Funnel web spiders belong to the Agelenidae family and a popular species of this family includes the hobo spider.
The Uloborid family is often associated with this type of web. Hence their name, triangle webs, are silky strands of spokes and spirals that connect to three strands. Triangle webs are horizontal and fuzzy, which helps trap and smother prey. The Uloborid family is the only family of spider without venom glands, so their web’s fuzzy material compensates for the lack of their venomous bite.
Spiders build webs because they need them to survive. Their silk is incredibly strong and sticky, making it the perfect trap for catching insects like flies, mosquitoes, and moths. Once prey gets caught, the spider quickly moves in, injecting venom to subdue it. But webs aren’t just for hunting.
Some spiders use them as shelter, while others create egg sacs to protect their young. Webs also act like alarm systems, sending vibrations when something moves nearby. Without webs, many spider species wouldn’t be able to eat, stay safe, or reproduce.
Spiders are smart about where they place their webs. Outside, you’ll find them stretched between tree branches, under porch lights, in bushes, and along fences—anywhere insects are likely to fly. Indoors, they prefer quiet, hidden spaces like ceiling corners, attics, basements, and behind furniture. The type of web depends on the spider.
Orb-weavers make large, circular webs in open spaces. Cobweb spiders build messy, tangled webs in dark corners. Some spiders don’t even spin webs to catch food—they make silk-lined burrows or draglines instead. No matter where they build, their goal is the same: catch prey while staying safe from predators.
Spider webs are made of silk, a special protein that spiders produce in their bodies. It starts as a liquid and turns solid when exposed to air. This silk may look delicate, but it’s actually stronger than steel of the same thickness. Spiders don’t just spin one type of silk—they produce different kinds for different jobs.
Some silk is sticky to trap insects. Other silk is tough and used for structure. There’s even silk that’s stretchy like a bungee cord. This incredible material allows spiders to build traps, wrap prey, and even create "parachutes" to float through the air.
This likely means spiders are making themselves comfortable. They may have come inside searching for food, warmth, or a safe place to hide. Gaps around windows, doors, and vents make it easy for them to sneak in. Once inside, spiders like to look for quiet, undisturbed areas—corners, closets, basements, and garages—to spin their webs.
Regular cleaning and sealing of entry points can help reduce webs, but spiders are persistent, and if you suspect you have an infestation, you’ll need help from a professional spider exterminator.
Spiders can be found in most properties throughout the United States but certain species are more prominent in the Pacific Northwest. These species include:
Black widow spider
Wolf spider
Hobo spider
Giant house spider
American house spider
Whether it’s spider identification or spider control, your local Western Exterminator pest technician can keep your home clear of spider webs. To learn more about our spider control services, call 800-937-8398 or contact us online.
Some spiders reuse their webs, while others rebuild them daily. Orb-weaving spiders often eat their old webs to recycle the silk and build a fresh one. Other species, like cobweb spiders, leave their webs up and make repairs as needed instead of starting over.
Spider webs help spiders catch food. The silk is sticky and strong, trapping insects that fly into it. Webs also provide shelter, protect eggs, and help spiders sense vibrations from prey or threats. Some spiders even use silk to travel by "ballooning" through the air.
Not exactly. A spider web is an active, in-use web where a spider lives. A cobweb is an old, abandoned spider web that has collected dust. Cobwebs are often left behind by spiders that no longer live there or have died.
Cobwebs originally come from spiders, but once abandoned, they collect dust and look like they formed on their own. Over time, airflow can tangle silk strands together, making cobwebs appear even when no spider is around.
Yes, cobwebs are old, unused spiderwebs. Many belong to house spiders that once lived there but moved or died. As dust sticks to the silk, the web becomes more visible, making it look different from a fresh, active spider infestation.
Yes, removing cobwebs helps keep your home clean and discourages spiders from returning. Regular dusting and vacuuming can help prevent buildup. But if you keep finding cobwebs, it may mean you have active spiders, and professional pest control can help remove them.
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