Everytime I go off my usual trail/hike I discover something awesome like this small neato rock shelter...which leads to more awesome stuff, like creepy long legged cave dwelling spiders! In the pic above that is me putting my hands on the top of the rock ceiling suddenly discovering I had put my hands into a massive colony of spider webs. These well camouflaged spiders are huge, I mean they make the daddy long legs look short and would probably make an arachnophobic faint.
The ghostly cylindrical white stuff in the image below are the funnel webs they build. Each spider up there had it's own personal style of "funnel" including some that were tornado or bell shaped. Surrounding the funnel webs were these intricate and nearly invisible cross hatched webs that seem to have no shape or pattern, but were simply a death trap for anything that may crawl on the rock.
The webs spanned outward, covering a large area not only on the ceiling of the rock, but all the way out the 'door'.
The only thing that gives them away is their web - because otherwise they look just like the rock! And that's if ya see the web before you stick your fingers or head into it first. :)