How spiders live and behave?

Silk, the secret of success
　
One major reason for the success of spiders is the silk they produce and the ways in which they use it.
　

Spider silk is mainly made up of proteins. It leaves the spider's body as a liquid which hardens rapidly in the air, then does not dissolve in water. It is very strong, and can stretch to add one-third more to its length, then snap back to its original length without change in shape.
　
Silk is produced in glands which make up a large part of a spider's abdomen. Different glands make different sorts of silk to be used for purposes including the manufacture of egg sacs, lining shelters and constructing webs. Silk is also used for the safety lines many spiders drag behind them, which save them if they fall. Young spiders spin silken threads on which they "balloon" through the air.
　
Many tiny tubes connect each silk gland with a spinneret. The sticky fluid which coats the strands in orb webs and catching lines is applied in these tubes.
　
Mate, not dinner
A female spider is often much larger than a male of the same species, and is sometimes quite different in appearance. Courtship is lengthy, for the male must convince the female he is a mate and not prey.
　
To introduce himself, a male may posture, dance, pluck a female's web or present gift-wrapped prey. He spins a special web, expels sperm onto it, then sucks the sperm into bulbs on the ends of his pedipalps. When he judges it is safe to do so, he inserts the end of a pedipalp into the female's reproductive opening and discharges the sperm it carries.
　

The female stores the sperm until she is ready to lay eggs. She may lay 100 at a time, protecting them in a silken egg sac.
　

Sacs and tiny spiders
　
Silken egg sacs may be hidden in vegetation, or in crevices, or buried in the ground. Most are guarded. The sacs may be carried around on the spinnerets, between the legs or in the jaws. Female wolf spiders may allow young to climb on their backs and transport them.
　
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Camouflage
Spiders may rely on camouflage to protect them from predators such as birds. They may blend in with the colour or texture of their background in order to lie in ambush waiting for their own prey. A wraparound spider has a broad abdomen which is so flattened that the spider can wrap itself around a twig. Bird-dropping spiders and crab spiders are also well camouflaged by colour and texture. Some spiders mimic insects such as ants.