While all spiders spin silk, not all spiders make webs with their silk. Some spiders actively hunt prey instead of passively catching it in a web, including Leaf-curling Sac Spiders. They utilize their silk to form a protective brooding chamber for their eggs by stitching the underside of a leaf together. Within this shelter the mother spider first constructs an egg sac from strong silk that is tough enough to protect her developing offspring from the elements. She then deposits her eggs inside it, fertilizing them as they emerge. A single egg sac may contain just a few eggs, or several hundred, depending on the species. The mother spider remains within the shelter protecting her eggs until they hatch. Look for these spider shelters on the under side of grape leaves.
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