After her sister Aëdon won a bet against her husband
Polytechnus, Polytechnus was forced to find his wife a slave. He went to Pandareus, claiming that Aëdon wanted to see her sister. Chelidon left with Polytechnus, but he forced himself on her, cut her hair short, and dressed her up as a slave, terrorizing her against telling anyone what had happened. He then gave her to Aëdon as a slave. Aëdon did not suspect anything until one day she overheard Chelidon lamenting her cruel fate. The two sisters then killed
Itys, Aëdon and Polytechnus's son, and fed him to his father while they ran back to their own. Polytechnus hunted them down, but Pandareus protected his daughters and had Polytechnus tied up, smeared with honey and left to the mercy of flocks of flies. But Aëdon, feeling sorry for her husband, kept the flies off of him. Pandareus, his wife and the unnamed son attacked her, so
Zeus decided to turn them all into birds. Chelidon became a swallow.[2][5][6]