Booby traps on trails to or around marijuana fields include audio/visual signals (trip flares, air horns, munitions simulators, smoke grenades, shotgun blanks, fireworks, and ground sensors) and explosive devices; the latter may be hand grenades, pipe bombs, improvised mines, small arms ground spike, fragmentation devices, incendiary devices, and firearms. Some booby traps require a physical action before they will function, such as the pulling or releasing of a tripwire, foot pressure, pressure release, and devices that require vibration to activate them. Some nonexplosive devices used to guard marijuana fields are poisonous snakes, fish hooks hanging at eye level, punji sticks, animal traps, concealed pits, and guard dogs. Some "do's and don'ts" in approaching or anticipating booby traps are listed, and advice is offered on what to do when a booby-trap device is found. Various types of booby-trap systems for clandestine drug labs are described. Drawings are included to illustrate the design and operation of various types of booby traps.