system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5 How are electric fences "safe" considering the high voltage? And why is the high voltage necessary?

I understand basically that the current, or amps, are what cause harm, but based on Ohm's law, V=IR, for the amps to be so low with such high voltage, the resistance must be very high. So why do you need such a high voltage in the first place? Wouldn't that require a transformer to step up the voltage? And doesn't such a high voltage create a safety risk, for instance if a conductor with lower resistance came into contact with the voltage source? Or arc flash? If you want low amps as not to electrocute animals/people, would it not be easier to use lower voltage?

Just curious and trying to understand. Electricity is like magic to me.
gpt
You have a correct understanding of ohm's law. We need high voltage *because* the resistance of people and animals is so high. A lower voltage would not produce any meaningful current and then we wouldn't feel it. 

It may need a transformer or it uses an inductor (half a transformer) to boost the voltage using a DC-DC converter. 

If a conductor with a lower resistance touches the wires then it could start a fire. A good shock device should have the ability to detect when it is touching a low resistance object and either limit current artificially or shut down.