I electrified my fences and any critter that comes in contact with it doesn't seem to come back to test it out again. I have heard the critters come in contact. Make sure you have a good ground. My ground rod is a 10 ft rod with 8 ft in the ground. My power supply is good for 10 miles of fencing. My voltage averages around 6000 volts. I definitely know when I have touched it. I have a switch under my power supply so I can turn off the power if I need to.
This is an old picture and I have relocated the power supply and switch.

This is an old picture and I have relocated the power supply and switch.