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Only some threads are glued

Why Don't Spiders Stick to Their Own Webs?

Only the spiral threads are sticky, and the spider walks on the dry ones.

Spokes — dry The spider walks ontheseSpiral — glued These catch the prey
Two kinds of thread in one web.

  1. Step 1 of 5

    A web has two types of silk.

    Dry spokes forstructureSticky spiral forcatching

    The radiating spokes are strong and dry. The spiral wound across them is coated in droplets of glue. Spiders make several silks from different glands.

  2. Step 2 of 5

    The spider travels on the dry threads.

    1 The web isbuilt2 The spidermoves along thespokes3=It rarelytouches theglue

    Watch one cross its web and it steps along the spokes. It knows its own construction and avoids the glued spiral almost entirely.

  3. Step 3 of 5

    Their feet are built to resist it too.

    A spider's foot Fine oily hairs — almostno contact area

    Spider legs have fine hairs and an oily coating, so contact area with any glue droplet is minimal. Even a mistake usually does not trap them.

  4. Step 4 of 5

    The glue is in droplets, not a coating.

    Continuous coating Dries out quicklyBeads of glue Stay sticky, gripharder

    The sticky spiral carries beads of glue rather than a continuous film. Beads stay sticky far longer and grip struggling insects better.

  5. Step 5 of 5

    Silk is astonishingly strong.

    Spider silk, by weightstronger thansteelSteelstronger byvolume, not byweight

    By weight, spider silk is stronger than steel and far stretchier. The web absorbs a flying insect's impact without snapping.

    Many spiders eat their old web each night and recycle the protein into a new one.

The short version

Only the spiral threads are glued, and spiders walk the dry spokes on oily, minimal-contact feet.

Try it yourself

Touch a web very gently with a dry twig at the spokes, then at the spiral. Only one grabs it.

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