In this capacity, Apollo was called by the name Paean, once a distinct god, whom he absorbed into himself. Apollo was also father of the healing god Asclepius, whose cult was widespread in the Greek world. In Homer s Iliad, Apollo is addressed with his epithet Apollo Smintheus, or Apollo the Mouse God . The Greeks associated Apollo with mice and so prayed to him under that name because they recognized that rodents were vectors of disease, although they did not realize that it was actually the microorganisms on the fleas on the rodents and not the rodents themselves that were harmful. They recognized the correlation between plague and rodent infestation and so prayed to Apollo Smintheus to abate plagues.
Greek myth is often merely an allegory for an historical event.
One of the canonical Twelve Labors of Hercules involved ridding the swampy district of Lernea of a multi-headed serpent known as the Lernean Hydra. Every time Hercules cut off one of the serpent s heads, two more grew in its place. Archaeologists believe this myth actually commemorates an historical plague which devastated the population of ancient Lernea. The rapid spread of whatever sickness gripped the region corresponds to the duplicating heads of the serpent.