Electric fences, to control livestock, are common in Europe and usually pulse high voltage with a very low amperage and can be battery or mains powered. You can usually hear them 'ticking' every few seconds or so.
Cows are very sensitive to electric shock, and the amperes must be very low to avoid costly mortalities! Many years ago I built a system from an automotive ignition coil and an old mechanical car voltage-regulator to pulse the volts, (the ground is the return path). Ran it off a 12v truck battery to keep our sow out of the veg patch. Once she got a belt, she would not go near a wire again ( fouth most intelligent animal on earth!), so we eventually turned it off and put up some string. Actually, it stung our dog once as well. He turned round and bit the wire, but he did come back in a day or two!
But Mantraps are illegal in the UK following horrendous injuries to trespassers and poachers in the 19C. These sometimes consisted of gigantic sprung gin-traps 5 feet across and able to almost cut a man in half.
Recently, a Farmer was prosecuted after he set an electric fence-machine to protect his Land Rover from persistent vandalism at a local farmers' market.
Result at the High Court was that electric shock applied by a non-lethal method to deter theft was legal, and not a man-trap.
Not guilty.
My favorite tale is the old man plagued by a persistent pair of burglars. He sawed out the floor over his basement and tacked the carpet to the baseboards. The Burglars fell eight feet into his cellar and broke their legs. He got prosecuted too.
Alan
