Herakles failed to drive them off with his arrows. Athena gave him a set of metal castanets (or a rattle) made by the blacksmith of the gods, Hephaestus. Herakles climbed to a rocky place over the lake and made so much noise with the castanets that the birds flew as far as the Isle of Ares in the Black Sea. Herakles was able to kill many of them with his arrows as they flew away. 