Did you know? Spider silk is five times as
strong as steel!
Scientists have discovered why spider webs are able to withstand
huge forces without breaking. To find out how much force spider
webs can stand, scientists tested real spider webs and ran computer
simulations. They found that some spider webs can withstand
hurricane-force winds!
Super strong silk
Although silk is very strong, that's not the only important
factor in a web's strength. Spider webs have a very complex design.
The way the web is built means that if a single strand of web
breaks, the strength of the web actually increases. Pretty
impressive from a humble spider!

A spider web becoming stronger when a thread breaks is an
incredibly clever material property. Imagine if we built objects
that, when a bit broke off, the objects got stronger! Scientists
hope that this finding could be used to help design new super
strong materials.
Scientists also found that spider silk can react differently to
different types of forces. If a light wind blows on the web, the
silk softens and becomes more flexible. The spider web can blow in
the breeze without breaking. If a larger force is applied to one
part of the web, the silk in that part of the web becomes stiff and
one or two threads break. The rest of the web stays intact.
Why do spiders need strong sillk?
These unique properties of silk are very important for spiders.
It takes a lot of energy to build a web. If only a couple of
threads break, the spider doesn't have to start building a whole
web from scratch. Also, spiders need their webs to catch food. If
the web broke every time an insect flew into it, it wouldn't be a
very good trap! Instead, the web is flexible enough to stretch when
an insect lands in it, strong enough not to break and sticky enough
to trap the insect.
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