Web is an environment object found throughout Area 1 and due to its effects is considered a trap. Spelunkers can also make their own webs using a web cannon. When you walk or run through it, you will become slow and unable to jump more than half a square up. Repeated jumping will cause the web to dissipate and eventually disappear. If you fall into a pit with it, this process is necessary. Enemies can also be caught in webs which will render them immobile, the exception being spiders, giant spiders, and the ghost. Webs can also be used to traverse large gaps, by using the web cannon to create a "bridge" of them, then moving across the resulting arc of webs while rapidly pressing jump to keep from falling through.
Giant Spiders will invariably be generated with a pair of webs beneath them.