Zombie Decomposition and Terrain

The "natural" life span of zombies is dictated by their rate of decay. In the unfortunate event of non-human-instigated-brain death, a zombie will continue to function until it simply decays into nothing. According to Max Brooks this can happen in three to five years, due to mircobiotic aversion (pages 10-11). However, this is largely dependent on environment.
Zombies, while mostly impervious to the bacterial digestion that causes decay, are very susceptible to everyday wear and tear. While we avoid physical damage naturally, so that we also avoid pain, zombies feel no pain (page 9). Therefore, they are oblivious to the continuous small damage they are taking. Since zombies also do not have the ability to heal (pages 9-10), this damage can add up, accelerating the decaying process.

Knowing this, selecting your terrain to increase the accumulation of damage, can be a valuable tool for increasing your chances of survival. If, for example, you relocate to the top of a rocky/craggy hill, which is alternately covered with moss and sharp rocks, by the time the zombies get to you they are going to be in sad shape and much easier to pick off.

Advice of the Day: Use the zombies weaknesses against them.