How can spiders move about their webs without becoming caught

A.� Because the spider spins at least two different types of silk: sticky and not sticky. The spider uses non-sticky silk to form the spokes of its web, saving the sticky silk for the spirals that circle out from the centre of the web.

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They also use their mouths to smear a non-stick solution over their feet.

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If you threw a spider against its own web, like most things, it would stick.

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Q.� How can spiders make two kinds of silk

A.� Most can actually make up to six different types. Spiders have at least four, some times six, individual spinnerets, the body part that generates the silk. Different spinnerets make either sticky or non-sticky silk by either applying or not applying a coating of tacky residue on the strand as it comes out.

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Other types of silk are spun for different tasks such as wrapping up prey and protecting eggs.

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Q.� How often do spiders spin their webs

A.� Some spiders live in their webs for a long time, while others, including the garden spider, remake them every night. Spiders normally eat their webs, which are packed full of protein, recycling up to 90% of the materials.

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Q.� Can any other invertebrates spin webs

A.� Yes, although no other animal can spin a web quite as spectacularly and efficiently as a spider can.

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Q.� How do spiders build webs

A.� It’s a skill they’re born with. The strands of non-sticky spokes and sticky spirals are woven over a basic scaffold that is eaten by the spider once the completed web is in place. The scaffolding is built from the centre outwards and the web itself from the outside into the centre.

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Q.� What is spider silk made from

A.� Spider silk is a fibrous protein.

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Q.� How tough is spider silk

A.� Very, once the fibre has been spun, it hardens, becoming stronger than a length of steel with an equal diameter, its elasticity adds to its resistance. Most of the silk threads in a spider’s web are multiple strands of fine silk lying alongside each other.

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Q.� Are webs only used for trapping prey

A.� No, silk is used by males for transferring sperm, by females to make cocoons and can be used for lining burrows. Baby spiders use silk to make parachutes to carry them long distances to fresh pastures.

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by Lisa Cardy