I have 8' ground rods. If it is placed in a drip line it is more effective as the ground there tends to me more moist. Only around 4 to 6 inches of mine stick above the ground to connect my ground wire. You can have more than one ground rod too. Also the charger has to be powerful enough to hurt the predator so it will get the message. If it isn't a quite strong zap the predator can get used to the tickle and go right through it.
	
		
			
		
		
	
				
			 
	 
 
		 
			
		
		
		
	
	
			
		 
			
		
		
		
	
	
			
		 
			
		
		
		
	
	
			
		 
  You need a ground. You could put a piece of metal grounded along the top and a hot wire barely above it so the critters would have to touch the grounded metal and the hot wire. Years ago we had a serious issue with gray squirrels. As soon as we filled the bird feeders here would come the squirrels. My DH ran a hot wire on the perch wrapped with tin foil and grounded a metal feeder so when the squirrels got on the perch then reached across to the bird feeder they were zapped. Most learned their lesson. I do have electric wires around my coops and pens and the predators seem to be aware. I know some have tested them and once is enough. Good luck...
You need a ground. You could put a piece of metal grounded along the top and a hot wire barely above it so the critters would have to touch the grounded metal and the hot wire. Years ago we had a serious issue with gray squirrels. As soon as we filled the bird feeders here would come the squirrels. My DH ran a hot wire on the perch wrapped with tin foil and grounded a metal feeder so when the squirrels got on the perch then reached across to the bird feeder they were zapped. Most learned their lesson. I do have electric wires around my coops and pens and the predators seem to be aware. I know some have tested them and once is enough. Good luck... 
 
		 
 
		
 
 
		 
 
		 
 
		 
 
		 
 
		 
 
		 
 
		 
 
		 
 
		 
 
		 
 
		 
 
		 
 
		 
 
		 
 
		