Encyclopædia Britannica, Ninth Edition/Æacus
Æacus, in Mythology, the son of Jupiter by Ægina. When the isle of Ægina was depopulated by a plague, his father, in compassion to his grief, changed all the ants upon it into men and women, who were called Myrmidones, from μύρμηξ, an ant. The foundation of the fable is said to be, that when the country had been depopulated by pirates, who forced the few that remained to take shelter in caves, Æacus encouraged them to come out, and by commerce and industry to recover what they had lost. His character for justice and piety was such that, in a time of universal drought, he was nominated by the Delphic oracle to intercede for Greece and his prayer was answered. The ancients also imagined that Æacus, on account of his impartial justice, was chosen by Pluto one of the three judges of the dead, and that it was his province to judge the Europeans.