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All spiders, to varying degrees, cover their eggs with silk, a few primitive species with just a few strands and others with a dense layer of silk in the form of a discrete egg sac.
Many female spiders carry their egg sacs with them or guard them in other ways.
These behaviors are, of course, elementary forms of parental care. Some spiders give more elaborate care to their young.
Female wolf spiders carry their egg sacs with them everywhere, and when the eggs are ready to hatch, the mother tears the tough egg sac open so that her babies can make their way out.
They immediately scuttle up onto her abdomen and ride there until they are ready to begin feeding, at which time they drop to the ground.
A European spider, Theridion, provides a far more advanced form of parental care.
The female closely guards her egg sac, which hangs in a protective tent in the upper part of her web.
For several days, the newly-hatched spiderlings feed on a liquid that oozes from the mother’s mouth. They share the mother’s food, eating liquids that ooze from wounds that she makes in the tough outer shell of the prey.
Eventually, the young grow large enough to help their mother make captures by throwing strands of their own silk over the struggling insect.
When the mother ultimately dies, her offspring eat her body, her last contribution to the welfare of her babies.