Re: Is a 'daddy long legs' a spider, what does it eat and it's real name?

A true daddy-longlegs (also called a harvestman) is an arachnid, but not a 
spider.   Spiders are arachnids with two major body parts, while true 
daddy long legs have all body parts fused into what appears to be one pill-
like mass (the abdomen part of the pill is segmented, but the segments are 
usually not distinct to the eye).  True daddy-longlegs are in the order 
Opiliones or Phalangida (you see both used in various books), while 
spiders are in the order Araneae.  There are spiders that have been called 
daddy-longlegs spiders (family Pholcidae), but these build webs and 
obviously have two distinct body parts.  True daddy long legs do not 
produce silk, as spiders do. Daddy-longlegs, like most arachnids, are 
predators, eating small invertebrates.

Reference:

Arachnology: The Study of Arachnids- Opiliones.  http://www.ufsia.ac.be/Arachnology/Pages/Opiliones.html