What is the ruling on one who kills a mouse while standing at Arafat?

The Lawgiver has permitted a pilgrim in the state of ihram to kill anything that harms people, such as a mouse. This is based on the hadith of Aisha, may Allah be pleased with her, that the Messenger of Allah, peace and blessings be upon him, commanded the killing of five harmful creatures (fawasiq) both inside and outside the Haram (sacred precinct): the crow, the kite, the scorpion, the mouse, and the rabid dog. The "fawasiq" are harmful creatures that are exempt from the general prohibition of killing. Therefore, there is no blame on someone who kills a mouse in Arafat.