U.S. Air Force Staff Sgt. Noah Medor, 633rd Security Forces Squadron military working dog handler and Ali, 633rd SFS military working dog, practice explosives detection at Joint Base Langley-Eustis, Virginia, Feb. 26, 2019. When a dog has caught the scent of an explosive he lets his handler know by sitting down. (U.S Air Force photo by Senior Airman Anthony Nin Leclerec)