I have a 12x12 chain link enclosure 7' tall. It is covered by bird netting. I had a raccoon scale the fence and drop inside when the bird netting tore. Rather than trying to cover the entire top in chicken wire (I would need to make a truss structure to hold the wire 3' above the 7' pen so I can raise the top of my henhouse now and then whereas now I just raise up the bird net) $$. Why not put an electric fence on insulators about 3" above the top frame of the enclosure? Seems quick, easy and effective.