Bagworm or Case Moth caterpillar

Psychidae

Description:

Bagworms "…construct cases out of silk and environmental materials such as sand, soil, lichen or plant materials. These cases are attached to rocks, trees or fences while resting or during their pupa stage, but are otherwise mobile." (Wikipedia)

Habitat:

This critter carrying his home was climbing all over a stack of papers - though looked like he was almost going to topple over at one point (see last photo).