Daddy Long Legs or Harvestmen are one of the most well known insects in the world. Contrary to popular believe, they are not true spiders at all. There are over 6,500 different species of Daddy Long Legs which are also called Pholcus phalangioides, Cellar Spiders and Skull Spiders! Pictured below is a common species known as Phalangium opilio. As you can see they get their name from their long legs in comparison to its body. 
There is an urban legend that claims that Daddy Long Legs are the most venomous creature in the world, but lack the fangs to bite a human. This is not all all true, in fact, this spider has no venom glands or fangs, instead they have chelicerae.Daddy Long Legs spiders will often feed on small insects, fungus, dead organisms and fecal material. As you can imagine these spider fall prey to many different predators, but they have a few tricks up their sleeves. Daddy Long Legs will sometimes play dead and can also detach their legs which will continue to walk away and can confused would be predators. They also have special glands that act as a repellent against ants.
You can check out a Daddy Long Legs Spider in the video below...
Your photos depict Harvestmen, which is a family of species of arachnid, but which is not a spider. Actual spiders are a different family of arachnids.
ReplyDeleteThe video depicts an actual Daddy Longlegs spider.
Confusion comes because the term 'Daddy Longlegs' is used to describe both, but technically they are very different critters.
More info on harvestmen here:
http://en.wikipedia.org/wiki/Harvestmen
Hope this helps!