Nicky, a military working dog with Military Working Dog Platoon, 2nd Law Enforcement Battalion, II Marine Expeditionary Force Headquarters Group, chews on a tennis ball after tracking the scent of a Marine aboard Marine Corps Base Camp Lejeune, N.C., Oct. 9, 2014. Seven Marines and five canines conducted bite, tracker and patrol training, enhancing the dogs’ sense of hearing and smelling. (U.S. Marine Corps photo by Lance Cpl. Lucas J. Hopkins/Released)