Defense mechanisms are strategies used by individuals to protect themselves from psychological harm. DENIAL is a defense mechanism in which an individual refuses to accept reality or facts. An ALIBI is a defense mechanism in which an individual provides an excuse for their actions. MACE is a defense mechanism in the form of a chemical spray used to temporarily incapacitate an attacker. A MOAT is a defense mechanism in the form of a deep, wide ditch filled with water that surrounds a castle or other structure. RADAR is a defense mechanism in the form of an electronic system used to detect the presence, direction, and speed of aircraft, ships, and other objects.