Many spiders do not make webs (wolf spiders, jumping spiders, etc.). They use their silk as a rescue line (if they drop down somewhere), fast travel tool (spiders can fly using wind and electromagnetism, in fact spiderlings are a major part of the "air plankton") and to make eggsacks (which protect their fragile eggs and act as first meal for the spiderlings) Some spiders even use their silk glads to produce a protein-rich "spider milk" which they feed to their young, much like mammals do.