There are always different ways to do these things and different details, but you have two different basic options, netting or wires. In both you have a very high voltage, very low amperage, and a pulsing current. Since it is pulsing you can turn it loose so nothing will get injured, but it will bite you. You don’t want to touch it a second time. For them to work, you need a ground to complete the current. That’s accomplished by the predator’s feet touching the ground. Practically any predator will go up to the fence to check it out instead of trying to jump over it. They’ll sniff it or lick it. Once they get bit, they leave and don’t come back. One guy on here spreads peanut butter on the wire to invite the predator to lick it. They get a real good ground with that wet tongue. And they don’t come back.
I get very pleased when a strange dog goes up to my netting and sniffs or licks it. You hear a yelp and then see the dog running away. A very satisfying feeling. My chickens are safe with no animal getting hurt.
One basic option is the one I have, electric netting, which I got from Premier. It is a net where all the horizontals are “hot” except for the very bottom one. Anything that touches a live wire and the ground at the same time will get bit. The netting is tight enough that a grown chicken cannot walk through it but a baby chick can just walk through maybe until they are a month or more old. Their down insulates them.
Mine can fly over it (4’ high), but they don’t because they don’t want to. The top does not look like something they can perch on, so they don’t fly up to perch. Chickens can fly pretty well, but they won’t unless they have motivation. As long as the area inside is big enough and they don’t have something chasing them, they have no reason to fly over it.
I’ve had a chicken get out under two different circumstances. You can set the netting up in different configurations. I once set it up long and narrow and a hen got out within a few hours. I think she got trapped against the end by a rooster wanting to mate and she couldn’t get around him to run away so she went vertical and landed outside the fence. That’s the only time I’ve had a hen fly over. I always have a wide configuration now, never long and narrow.
I always raise young chicks with the flock. Often when the cockerels are in adolescence one or two will fly over the netting in a week. When they are having their pecking order/dominance confrontations, the loser runs away. If it is caught against the fence, it goes vertical and winds up on the wrong side.
The wiring is different. Unless you have a really large area you need some type of fencing to keep the chickens in. But you need to insulate the electric wire from the fence, including the fence posts. You attach insulators to the fence posts to insulate the wire electrically from the fence. Normally you have two electric wires. One is really close to the ground so any predator low to the ground will touch it and not just go under the fence; raccoons possums, skunks, foxes, dogs, most of your biggest problems. But then you have another wire higher up so anything trying to climb is bound to touch it. They’ll ground out on the fence itself so they don’t have to be touching the ground when they hit the hot wire.
The netting is best for a temporary fence. You can relocate it if the forage inside is eaten. The wire is best for a permanent fence that does not move but will easily cover a much bigger area.
Both have one flaw. If the grass or weeds grow up into it to touch the hot wires, they’ll ground out the fence when they are wet, either from rain or dew. You have to have a system to keep the grass and weeds from grounding it out. Lawn mowers and weed eaters are death to the netting and probably to the wire. With the netting you can mow an area and set the netting back up. In the periods of the year when grass is growing fast, that might be every two weeks or so. Some people who pasture their chickens will move it about every day for fresh forage. Like I said, different details. I spray my border with round-up to keep the growth down. I don’t know how the people with permanent fencing do it.
You can get a kit from Premier that has everything you need for the netting. That’s what I got. Premier will answer the phone and talk to you. I’m sure you can get kits for the wiring too. They are kind of expensive and they need some maintenance, but they are very effective against ground predators when installed properly. They don’t do anything against birds of prey however.