Musnad Ahmad 1153:1293

Ya'qub narrated to us, from the nephew of Ibn Shihab, from his uncle, who said: Urwah ibn al-Zubayr informed me, from Aisha, the wife of the Prophet, may God bless him and grant him peace, that the Messenger of God, may God bless him and grant him peace, said: "Five of the animals are all harmful (fasiq); they are to be killed in the state of ihram and outside of it: the biting dog, the scorpion, the crow, the kite, and the mouse."