Why do the undead prey upon the living? If it has been proven that human flesh serves no nutritional purpose, why does their instinct drive them to murder? Modern science, combined with historical data, has shown that living humans are not the only delights on the undead menu. Any creatures, no matter what their size of species, will be consumed by an attacking zombie. Human flesh, however, will always be preferable to other life forms. What can be confirmed, beyond any shadow of doubt, is that instinct brought on by Solanum drives the undead to kill and devour any living creature they discover. There appear to be no exceptions.