Decomposition is a necessary part of nature and begins at the moment of death. Bacteria and the bodys own internal chemicals start gnawing away at organs, muscles and skin. The skin will rupture and emit gasses, leaving gaping wounds in the corpse. From carrion beetles to vultures, animals play an important process in breaking apart the dead as well, and theres no reason they wouldnt be interested in zombies. Decay can be affected by many factors including temperature, humidity, rainfall, wounds and body size. In tropical areas, flies can skeletonize a corpse in two weeks. So, any zombies along the equator are skeletons in short order. It wouldn't take months for them to fall apart, especially not in places like Atlanta, Austin or Barcelona. In drier and colder climates, the decomposition process would be halted and the body would mummify, but again, they wouldn't survive for months. By the way, any living dead in Saskatchewan are really screwed when theyre frozen over for a good portion of the year.
