Re: Cats at 40,000 volts
I had this same problem with neighbourhood cats in my garden. Following advice from a friend, I hid a few little bird spring traps in the most visited areas. After a few days and several noisy incidents, the cats stopped using my garden as a loo.
Funny thing is, this happened some 15 years ago and the cats never returned. It's as if the buggers had some kind of oral tradition. 8^)