The U.S. Army's lack of familiarity with sniping tactics proved disastrous in Normandy and the campaign in Western Europe where they encountered well trained German snipers. In Normandy, German snipers remained hidden in the dense vegetation and were able to encircle American units, firing at them from all sides. The American and British forces were surprised by how near the German snipers could approach in safety and attack them, as well as by their ability to hit targets at up to 1,000m. A notable mistake made by inexperienced American soldiers was to lie down and wait when targeted by German snipers, allowing the snipers to pick them off one after another. German snipers often infiltrated Allied lines and sometimes when the front-lines moved, they continued to fight from their sniping positions, refusing to surrender until their rations and munitions were exhausted.