Upon first glance, this cluster of Daddy Longlegs looks like a puff of mold or moss. It's the type of thing I would sit next to without a second thought, not knowing what it really is.
I was horrified to watch the "moss" slowly start moving as the man in the video startled the Daddy Long-legs. Watching them all break apart from the big cluster gave me the chills.
I feel pretty bad for any unlucky soul who comes across a Daddy Long-leg cluster unknowingly. Or worse, sits on top of one thinking it's just a nice little bunch of plant sprouts.