I'm curious how you did this?
If you want perfect, 100% exclusion you will need three hot wires:
- one about 4" below top of fence, but only 2" out from the face of the fence
- one at roughly top of fence, but 4" out from the face of the fence
- one 2" above the top of the fence, in line with the face.
... which gives you a negative (?) overhang for a climber and the top wire is insurance that they can't somehow reach/slink over the first two.
100% success over 36 months against families of raccoons who were irresistibly attracted to (otherwise) defenseless chickens. Yes, raccoons > cats both physically and mentally.
So again, how does one prevent that? To me, it's really not even worth attempting as it will always be futile. The only thing that has really slowed down the backyard visitors in my yard is by allowing my cats to mark the area as theirs. After a couple of skirmishes, the other cats learn it's not worth it in that area.
Yes, our chicken runs are in a quarter acre cleared area.
This would not work with overhanging trees.
If there is an Einstein amongst cats I think there is still a viable path through a tree that is relatively close to fence but it would require some pretty tricky jumps and there would be no way back out.