How Do Spiders Spin Webs? Building an Orb Web Step by Step

Step 1: The bridge line

Every orb web starts with a single thread. The spider climbs to a high point, such as a twig or the corner of a window frame, and lets a fine silk thread drift out from its spinnerets. The breeze carries the thread until its loose end snags on something.

The spider feels the line go tight, pulls it taut and fixes it. It then walks across, laying a second, stronger thread as it goes. This bridge line becomes the top of the web, which is why garden spiders often build in gaps between shrubs, fence posts or plants that the spider could never cross by walking.

Step 2: The Y and the first spokes

Next, the spider hangs a loose thread below the bridge line and drops down from its middle on another thread, pulling the loose line into a Y shape. The point where the threads meet becomes the hub, the center of the future web, and the three arms of the Y become the first spokes, or radii.

From here the spider builds the frame: strong outer threads that enclose the web and are anchored to plants or walls at several points. These are made of tough dragline silk, the same silk the spider uses as a safety line, described in how spiders make silk.

Step 3: More radii and the hub

The spider now adds more radii, walking out from the hub along one spoke, attaching a new thread to the frame and pulling it tight on the way back. It fills in the web roughly evenly, checking the angles between spokes with its legs. A garden spider’s web usually ends up with a few dozen radii.

When the spokes are complete, the spider reinforces the hub with a few tight turns of silk. The hub is where the spider will sit, so it must be strong.

Step 4: The temporary spiral

The spider then lays a widely spaced spiral of dry, non-sticky silk, working outward from the hub towards the frame. This temporary or auxiliary spiral is scaffolding: it holds the radii steady and gives the spider something to walk on while it builds the final spiral.

Step 5: The sticky capture spiral

The last and longest stage is the capture spiral. Starting at the outer edge and working inward, the spider lays down a stretchy thread coated with tiny droplets of glue. It uses its legs as a measuring tool, reaching from the previous turn to judge the spacing, so the turns are evenly spaced.

As it moves inward, the spider cuts away and often eats the temporary spiral, which is no longer needed. Near the hub it stops, leaving a small open zone without glue around the center. This free zone lets the spider move between the front and back of the web and keeps its own resting place free of sticky silk, one reason spiders don’t stick to their own webs.

Some spiders then bite out the center of the hub. The European garden spider either waits head down at the hub or hides in a nearby leaf, holding a signal thread that tells it when prey hits the web.

How long does it take, and how often is it rebuilt?

A garden spider can complete an orb web in about 30 minutes to an hour, much of it spent on the capture spiral. Many orb weavers build at night or in the early morning, so the fresh web is ready when insects are most active.

Webs do not last. Dust, rain and struggling insects damage them, and the glue loses its stickiness. Many orb weavers therefore replace their webs every day or two. They eat the old silk before spinning the new web, recycling much of its protein.

Web building is instinctive. Spiderlings build tiny but correctly shaped orb webs the first time they try. Even so, spiders adjust their webs to the space available, the weather and their own hunger, making webs larger, smaller or more tightly meshed. In 1973, two garden spiders carried on the US space station Skylab managed to build orb webs in near weightlessness, although the webs were less regular than on Earth.

Other kinds of spider webs

Orb webs are only one design. Other spiders build very different traps:

Many spiders build no capture web at all. Wolf spiders such as the Carolina wolf spider hunt on the ground, and jumping spiders stalk and leap on their prey, but they still use silk for safety lines and egg sacs.