SPIDERS
If you look around the area where you live, you may notice
many different kinds of spiders.The world has anywhere from
40,000 to 120,000 different species of spiders. In any ordinary field,
two million spiders may be hard at work.They thrive in the hottest jungles
and the coldest polar regions. They have been found even at the height of
22,000 feet (6,700 meters), on Mount Everest! The spider's incredible silk-spinning
organs are on its abdomen. The silk thread begins as a liquid that hardens on
contact with the air. A spider can make many different kinds of silk thread. Each kind
has its own special purpose. By using certain tubes, or by combining the threads in
different ways, a spider can make a very delicate thread or a thick, broad band of
silk. Some sizes are used to line their nests or retreats. Others are used for egg
cocoons, or for tying up victims, or for weaving webs. Spider silk is stronger than
silkworm silk. If twisted into a rope.it can lift more weight than a rope of the same
size made of iron wire! In his book
Sociobiology, E.O. Wilson quotes an old
Ethiopian proverb, "When spider webs unite, they can halt a lion." Although lions
have never been seen in spider webs, there does seem to be some truth in this.
Scientists believe that cooperative prey-capturing in spiders has probably evolved
because it improves efficiency. It also allows the spiders to go after larger prey.
Cooperation and sharing improve the use of their webs and the food available to
them.
E X E R C I S E 1: Find words or phrases in the passage which mean the same as:
COLUMN A COLUMN B
a) do well; live successfully
b) part of the body; stomach
c) become stiff or solid
d) place in which to hide
e) cross threads over and under each other in
order to make something
f) net made by spiders from their silk in order to
catch food
g) to wind together
h) thin metal thread
i) say or write someone else's words
J) stop
k) catching animals forfood
I) change over the years due to environmental
conditions
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