Sleepwalking, also known as somnambulism, is a sleep disorder. Sleepwalkers arise from the slow wave sleep stage in a state of low consciousness and perform activities that are usually performed during the day. These activities can be as benign as sitting up in bed, walking to the bathroom, and cleaning, or as hazardous as cooking, driving, extremely violent gestures, grabbing at hallucinated objects, or even homicide. Major Evan Lorne suffered from this when he was young and after coming into contact with a crystal entity had an incident where he pointed a gun at Lt. Colonel John Sheppard, believing him to be a replicator. (SGA: "Doppelganger")