Our chickens are in a large yard, enclosed by a 6' plastic-mesh deer fence extending to the ground, with a hot wire (4000V) on the outside about 4" to 6" from the ground and a hot-tape about knee-high. Within this, on one side, we enclosed a run for the hatchlings, using smaller-mesh netting all around to keep the Ravens away. Today we found two dead chicks inside the run, one mostly eaten and another with just part of its head and neck eaten away. The wire was on and the tester still indicated 4000V. I could see where the predator had gone under the fence, somehow avoiding that hot wire, then tried to drag one of the chicks outside but left it just at the fence - maybe got hit by the wire on the way out? Can't believe that wire failed to work. I have a live-trap set up and hope to catch whatever it was -I'm betting opossum. Wish me luck!