The false, abnormal feeling that insects are crawling on or under one’s skin, often accompanied by stinging or biting sensations. Formication is a type of tactile hallucination. Its many causes include various medical conditions, altitude sickness, prescription drug side effects, and drug withdrawal.
Example: An alcoholic patient leaps from his bed and dances around the room in a frenzy, swiping at invisible insects on his arms and shouting, “Get them off me!”
Grinnell, R. (2011). Formication. Psych Central. Retrieved on May 6, 2015, from http://psychcentral.com/encyclopedia/2008/formication/