Took the dog for a twilight run on the levels this evening. Was on the return leg as the light was begin to fail completely. Had my headphones on pretty loud so when two army helicopters came over from behind me skimming the treetops, ( they do a lot of low level flying exercises here) the first I knew about it was when they were directly overhead. Scared the living crap out of me. I leapt about three feet in the air. I may have screamed. Dog freaked out too. Must have looked pretty funny to the boys in the helos.