Dax, 18th Security Forces Squadron military working dog, crawls through a tunnel during the obstacle course on Kadena Air Base, Japan, March 28, 2014. The tunnel was the last obstacle in the course, and Dax's hardest to understand, as he is a larger dog and believed he didn't fit through the tunnel. (U.S. Air Force photo by Airman 1st Class Hailey R. Staker)