Myths served a number of purposes for the Greeks. Many myths were etiological; i.e., they explained the origins of natural phenomena (e.g., "Where do spiders come from?") and social customs ("When we sacrifice to the gods, why do we get the meat while they get stuck with the bones wrapped in fat?") Many Greek city-states -- Athens, Mycenae, Sparta and Thebes, inter alia -- had foundation myths. These stories typically involved the gods and/or heroes such as Heracles. Foundation myths were important in that they helped to foster a sense of community.