Musnad Ahmad 27:96

Sufyan narrated to us, from al-Zuhri, from Salim, from his father, who said: The Prophet, peace and blessings of Allah be upon him, was asked about what animals a person in the state of ihram may kill. He said: "Five [animals] for which there is no blame upon the one who kills them within the Sacred Precincts: the scorpion, the mouse, the crow, the kite, and the vicious dog."