Page 58 - Wonderful Creatures: Children! Have You Ever Thought ?

WONDERFUL CREATURES

Garden spiders sometimes spin their

web between two distant branches.
Since such webs are quite large, they

are ideal for catching prey.
Nevertheless, their

large size results in a gradual decrease in
the tautness of the web, which means a

decrease in the ability to catch prey.
So spiders need a solution to this. You

might have thought that the spider would spin a
new web once the web is not taut enough any

more. But instead of replacing the web the spider
does something amazing: It secretes a thread from

the center of the web down to the ground, and fixes
a small stone on to that end of the thread which is

close to ground. Returning to the web and pulling
the thread, it lifts the stone. Then it fastens the thre-

ad, at one end of which the stone swings in the air,
once again on the centre of the web. Consequently,

the web is tightened up again as the weight of the
stone hanging from the web stretc-

hes it down.

You would probably not
come up with such a solu-

56