Spiders and their silk.

Their are two British spiders that have fangs that can break our skin, they are the dolimerer spider or the raft spider and the house spider. Spiders venom has evolved to prey on insects, they are no harm to other spiders. Spiders evolved three hundred and fifty million years ago, one third of all creatures we know on the planet are spiders. There are six hundred and forty five in the British isles. The name spider comes from the latinised Greek for spinner, and of course spiders are famous for silk.

So why is silk so good?

Silk starts life a watery fluid deep in the body of the spider, its then passed through some microscopic tubes that then remove the water and turn this complex of protein and amino acids into silk. It contains lots of hydrogen bonds, this is what makes it so strong. It then passes through the body until it gets to some muscular valves called spigots. It is then extruded from these and twisted into a cable by what are called the spinnerets, which is a tiny little organ on the backside of the spider.

There are seven different types of silk,

1,Egg sack silk- This is the silk the spider uses to wraps its eggs in.
2,Swathing silk- This is the silk the spider uses to wrap its prey in.
3,Dragline silk- This is the strongest of all the silks, the spider uses it to hang on.
4,Attaching silk- They hang this to any sub-straight.
5,Non sticky silk.
6,Sticky silk.
7,Sticky stuff- This is what makes the sticky stuff stick.

The silk is a incredibly thin fibre that's thinner than human hair. But it`s five times stronger than steel, and is almost as strong as the strongest man made substance-Kevlar-This is used for bullet proof vests. So have a think about how strong silk is the next time you walk into some in your garden.