If you mean sheep netting 1 mt high, if they are startled by something, they can jump or lean over it and tobble to other side, I once had 3 out one morning, going down a busy road to an other field opposite, but soon got them back with some veggies they are mad about. Best put 5" posts with a row or 2 of wire above.
Now all my fences are 6ft 2x2 weldmesh and all is happy lol
Mainly for my Wallabies and Emus...and my neighbours horses can't ruin them any longer.
Calla