There are a few different creatures that are often called Daddy Long Legs, but only one of them is a spider\rbr\rbrThere are a lot of myths associated with the name Daddy Long Legs, and a lot of consfusion regarding what creature that name ually referrs to.\rbr\rbrSpiders have a body that is divided into two parts, an abdomen and cephalothorax.\rbr\rbrUnlike spiders, the Harvestmans head and body is joined together.\rbr\rbrAlso unlike spiders, Harvestman have only two eyes.\rbr\rbrDaddy long legs are Members of the family Pholciae, and members of the family Pholcidae are sometimes called vibrating spiders.\rbr\rbrWhen the spider feels threatened, it vibrates rapidly in a gyrating motion within its web. Its not known exly why they do this, but it may be because:\rbr\rbrIt makes the spider appear blurred and difficult to focus on, making it difficult for a predator to see just where the spider is, or:\rbr\rbrIt may be intended to signal an assumed rival to leave, or:\rbr\rbrMaybe it increases their chances of capturing insects that may have just disturbed the web and may still be nearby..(their webs arent sticky) .\rbr\rbrOr, it could be all of the above. Or something else all together..we just dont know.\rbr\rbrBut, for this reason, Pholcids have sometimes been called Vibrating Spiders. though. they are not the only spiders that exhibit this behavior.\rbr\rbrThese spiders create messy, irregular webs which they cling to upside-down.\rbr\rbrThey prefer to set up in places that are cool, dark, and damp, which may be why they are also commonly known as Cellar Spiders.\rbr\rbrUnlike many other types of spiders, the of webs Daddy Long Legs are not sticky. Its thought that perhaps the highly tangled and irregular structure of the web may help in trapping insects.\rbr\rbrLike all spiders, cellar spiders are venomous, though their bites are not known to be harmful to humans. However, their bites are a big problem for a number of other types of spiders.\rbr\rbrAlong with capturing small insects, many species of the family Pholcidae often rely upon other spiders for food.\rbr\rbrDaddy long legs will invade the webs of other spiders, and may consume any food captured in the host spiders web, along with any eggs the host spider may have, and often will eat the unfortunate host spider as well.\rbr\rbrDaddy Long legs are natural predators of a number of different types of sipders, including huntsman spiders, the extremely venomous redback spider, as well as the many species of the genus Tegenaria. a genus that includes the hobo spider.(Tegenaria agrestis).\rbr\rbr\rbrDaddy Long legs use a trick when hunting for other spiders. By tapping on the web of another spider, the vibrations can mimic the struggling of a trapped insect, which draws the host spider close enough so that the daddy long legs can administer a deadly bite.\rbr\rbrMembers of the family Pholcidae are found on every continent except Antarctica.\rbr\rbrAmazing video of a Pholcid capturing a Black Widow:\rbr\rbr\rbrThanks so much to Brian Gratwicke, John Tann, Matt Mets, Andrew Gould, Corrie Barklimore, Richard Pigott, and David Short, for graciously allowing use of their wonderful images. Please do yourself a favor by visiting the links below to see more of their great work.