The most well-known method of delivering napalm is from air-dropped incendiary bombs. A lesser-known method is the flame throwers used by combat infantry. Flamethrowers use a thinner version of the same fuel to destroy gun emplacements, bunkers and cave hideouts. U.S. Marines fighting on Guadalcanal found them very effective against Japanese positions. The Marines used fire as both a casualty weapon as well as a psychological weapon. Men have a natural fear of fire. They found that Japanese soldiers would abandon positions in which they fought to the death against other weapons. Prisoners of war confirmed that they feared napalm more than any other weapon thrown at them.