1. The overwhelming desire to surround oneself in a protective fortification. The source of the desire can be varied, but for many the desire was popularized with the mainstream media's use of zombies to represent social discord. The emotion is often associated with having repeated thoughts of preparing for what a zombie apocalypse would bring to the world or watching way too many zombie style horror films. It should be noted the desire is also be experienced from any sort of social chaos concept that would make the beholder want to retreat from society whether the threat is real or perceived.
2. Overwhelming desire to board up windows. Occasionally treatable by closing the blinds unless you have an overactive imagination then its often worse.
I had a serious case of bunker hankering after watching every episode of "The Walking Dead" back to back last night.