A: If these insects are harmful, it becomes permissible to kill them with any insecticide but not with fire. The Prophet (peace be upon him) stated, "Five animals are harmful and can be killed while in the state of Ihram (ritual state for Hajj and `Umrah) or otherwise: A crow, a kite, a mouse, a scorpion

and a rabid dog." In another narration, he (peace be upon him) stated, "...and the snake." Thus, the Prophet (peace be upon him) informed us about these harmful animals and gave us permission to kill them. Similarly, any other harmful insects such as ants, roaches, mosquitoes and the like can be killed, whether in the state of Ihram or not.