Another Silly Question; Regarding Spiderling Behaviour

A few days ago I was looking over my photographic killing ground and found two very tiny spiders lurking about. I wrongly assumed they were some kind of dwarf species and was able to secure a few not-really-great shots for posterity since in most cases I almost never see very small spiders more than once. Well, last night I looked things over and saw that there were now three such creatures walking around and began shooting. Suddenly, I noticed a number of them swinging down on silk and the three others were laying lines horizontally. OK, this is unusual in that normally when a group of spiderlings come out like that they are looking for a breeze to move on with. These ladies were laying a giant trap together across the wall. They managed to catch a haul of mostly hoppers much larger than themselves and proceded to pounce en masse on the hapless victims. Over the next few hours they feasted together in small clumps around their victims. I have never seen social behaviour among spiders before except for spitting spiders which seemingly tend to live in small family groups. This phenomenon I observed first-hand for years at my old location in Montrose. It never occurred to me that true spiders do this as spiderlings, too. Is this not so odd and my inexperience is showing?