Kit Carson Scouts were former Vietcong guerrillas who had "rallied" to the government, frequently under the Chieu Hoi Program, and who were willing to act as scouts for U.S. units. New scouts would be closely watched and observed with suspicion, for they could not always be trusted. Some "rallied" only to work for the Vietcong as spies or to lead U.S. units into traps. Though, most were very reliable, risking and often losing their lives for the units they served. As a result, good Kit Carson Scouts were highly prized and treated accordingly by their units. They had familiarity with the terrain and culture, understood Vietcong tactics in establishing ambushes, and could identify booby traps. They also recognized Vietcong base and assembly areas from indicators Americans did not notice. Lastly, Kit Carson Scouts were able to identify Vietcong collaborators in villages as well as Vietcong masquerading as civilians.