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| Earth on Sep 13, 2012

How does a spider spin a web between two trees?

If you look up in a tree, you might see a spider web that spans a distance of a meter – several feet – or more. How do they do that?

Maybe you’ve seen spider webs strung high in the branches between two trees. How is the spider able to reach between this distance, which is often more than several feet?

The answer begins with the spider’s ability to transform liquid silk inside its special glands into solid threads. The spider does this by physically pulling the spider silk through its spinnnerets – silk-secreting organs on its abdomen. Once the thread is started, the spider lifts its spinnerets into the breeze. It’s the breeze that is the secret to the spider’s ability to spin a web from tree to another.

Spider webs via Kate Genet

Spider silk is very lightweight. Any slight breeze – even convection currents from a patch of ground warming in the sun – can carry the thread from tree to tree.

Although the thread isn’t sticky or gluey, it can still stick to the tree. Most likely it just gets tangled on small protuberances. Or it adheres due to static electrical forces, like balloons sticking to a TV screen.

At this point, the spider can use the thread to “tightrope walk” from one tree to another. Usually, the spider is hanging underneath the thread on its journey from tree to tree.

Many spiders build new webs each night or day, depending on when they hunt.

And spiders recycle – some eat their old webs and use the digested silk to produce new ones.

Bottom line: The breeze is the key to a spider’s ability to spin a web between two trees.

Nearly full moon shining into a spider web via EarthSky Facebook friend Jolynn Kautzer Bales