Soul Hunger

Soul-hunger expresses as a desperate need to consume in the undead. A living body has a natural hunger for when physical food is needed. It possess an innate sense of need. The undead body wakes with a new need for sustance, to refuel its Soul to maximum capacity, and only then will it feel sated. However, the body and the fragmented mind do not have a separate sense for soul-hunger. It only knows that it has an appetite, without instinct about the proper means to fulfill it.
This aimless hunger leads to the undead trying to physically eat anything they can find, particularly living creatures (as they are unknowingly being drawn to the fresh spring of Life they hold). In the basal state of uncontrollable hunger, they will merely rush directly toward anything living and attempt to grab and bite. In more aware stages, they might implement more selective methods which relate to their cultural myths about the undead.
For example, the Kobold race believes that the soul rests in the dragon fire of the belly (that is, the warmth separating a living body from a corpse). Kobold undead may try to rip open the belly and throat of their victim, nestle into their abdomen, and consume their warmth along with their blood and flesh. This occurs from a positive feedback loop wherein the kobolds believe this is a behavior undead perform, so the undead perform it, and it also actually works, so the undead perform it. It doesn't take long for these behavior patterns to form.
Using this more directed method does allow the undead to gain more Soul from the victim than they otherwise would from aimless chewing. There is no physical benefit from this, as the dead body is unable to process the nutrients, but it does sustain the various microorganisms to some degree.
Interestingly, for the more intelligent undead (e.g. Tier II and III), they can even learn methods from other cultures, and as long as they fully believe that they will work, the method will work. This means a Sarffi can use the kobold method of consuming Soul just as effectively after they adjust.

Type

Supernatural