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Stymphalian birds(stĭmfā`lēən), in Greek mythology, dangerous man-eating birds that infested the woods around Lake Stymphalus in Arcadia. As his fifth labor, Hercules frightened the birds into the air with a huge rattle and then killed them.
in ancient Greek mythology, birds with bronze wings, talons, and beaks that nested in Arcadia near Lake Stymphalia (Lake Zaraka). By casting off their arrow-like feathers the birds were able to kill animals and people. The destruction of the Stymphalian birds was the fifth labor of Heracles.