The crazy bug in the excellent post about the cave field trip is probably a kind of Laniatore, a suborder of Opiliones, the Harvestmen, which most people call Daddy Long-Legs. You can start searching for info on them in a wonderful, inexpensive little book, the Golden Guide to Spiders and Their Kin. Pages 128-130 or thereabouts. Laniatores are of no currently known medical or economic significance and as a consequence are hardly studied. Fascinating little creatures nontheless. Good for you for taking note of it.