Working on my coop . . . it will have an attached run . . . But, then, I'm going to fence off a pasture area, probably using 5ft high horse fence or whatever (2x4 mesh size) and probably a string of barbed wire above that. I want to put an electric wire around it to; I figure one near the ground and then one up higher, so in case something didn't get zapped below and was trying to climb up, it'd still get shocked. How far off the ground should the bottom strand, particularly, be for best protection against 4-legged varmints of all sorts?