How come spiders don’t get trapped in their own webs?

A spider web has sticky threads to trap prey. But the spider avoids the threads while weaving the web. Some spiders like the orb spider use both dry and sticky threads for the web, using the dry threads to step on. In case a leg is caught in the sticky thread, it wets the thread with its saliva. The chemical in the saliva dissolves the silk and frees its leg.