Daddy long-legs spiders are actually called cellar spiders.  We have heard people refer to them as bouncing spiders because when they feel threatened they will vibrate violently to intimidate predators. You are more likely to encounter these spiders in dark and damp places such as eaves, corners of your garage, basement, and cellar, where they can be seen hanging upside down in their webs. August is around the time that they are in full force in this area.  Most people believe that there is nothing we can do for these.  Once our customers get on our program the webs and spiders just disappear and never return.