Denny, a military working dog, rests after completing a joint demonstration with members of the U.S. Navy and U.S. Marine Corps at Camp Lemonnier, Djibouti, Jan. 13, 2014. Military working dogs are trained to defend bases and resources and to assist with enforcing military laws and regulations. They have the ability to conduct patrols and detect explosives or drugs, that a human working alone would be unable to locate. (U.S. Air Force photo by Senior Airman Tabatha Zarrella/Released)