Musnad Ahmad 27:1768

It was read to Abd al-Rahman: Malik, and Ishaq narrated to us, Malik narrated to us, from Abdullah ibn Dinar, from Ibn Umar, that the Messenger of Allah (peace and blessings of Allah be upon him) said: "There are five [types] of animals, whoever kills them while he is in the state of ihram, there is no blame upon him: the scorpion, the mouse, the vicious dog, the crow, and the kite."