to shock them they must not only touch the hot wire but be touching something else with a path to ground, so you would need a way to have two sets of wire without the movement of the tree making them touch. It will not harm the charger if they do, but you won't shock a squirrel if there are wires touching.

I suppose if you have a couple trees in town and did enough work with your wire it may be a good option. Or if there is a single path they take, like a chain link fence, you could try a hot wire down the top of the fence to interrupt the path.

best option is squirrel stew all winter.

If I wrap the trunk with the chicken wire, they'd be touching both the rooted tree and the live wire. Or, that's the theory.

From what I am reading the OP does not have enough basic knowledge with electricity and wiring to do set up something like this. There are also safety issues and those of injury to yourself, others, or damge to your electrical system if not properly setup with ground fault circuit interrupters.
I hate squirrels. Now that I have a cat and dog my options are getting reduced to live traps since poison and snares are out. Shooting with reduced loads is also an option with a lot of care and perhaps a shotgun which are real noisy.

If do that your breaker want throw the ground has to go back to box. What would do to tree I don't no.

The device linked to above has a transformer input and minimal power at the output, so the homeowner's electrical system is not at risk. Not enough current to damage a tree.

However, if the squirrel simply jumps up and contacts the chicken wire portion only, no shock will occur. Any time the trunk is dry, there is no grounding either. You might shock some of the squirrels some of the time. One user reported dead squirrels with a similar setup.

Yeah..chicken wire doesn't do it, you need ground in the same time, Squirrel would need to touch both in the same time, zapping only, [not killing] and squirrels will probably learn soon not to touch these wires. I'm thinking of wrapping both, live and ground wire onto something, like a rubber hose and about 1/4" apart,..but then they get smart and not going there no more.
When a cow touches the fence wire it makes ground, [bare hove] on the ground.

A fencer doesn't harm nobody.

I like the suggestion someone made a while back about floating sunflower seed on a barrel of water. Put a stick across the top. Squirrel jumps in and drowns. No noise or poisons. Just keep small children away from it. I haven't tried it yet, but sounds logical after we found 19 dead squirrels in our above-ground pool one spring when we had removed some floating styrofoam they were used to jumping down onto to get drinks. You might need to put the sunflower seed on a piece of plastic wrap to keep it from getting soggy.
Northwoodswis

It will never work. First you need GFCI breaker. Second they have to touch the wire and the ground to get shocked. The tree itself is a bad agent to complete the circuit. I am watching now 10 squirrel running and playing on the city electric wire which I am sure has high volt current and nothing happening to them because they are not touching the ground. By the way the wires are connected to the ground by wooden posts. Wood does not connect electric circuit.

Use two pieces of chicken wire, hook the ground to one and hot to the other. You could flare each end out about four inches and butt them together without touching to make him use that area. It might be a good way to potty train dogs too! if you have kids in the area they are bound to get shocked. It's not worth the risk.
To drown them use a half barrel of water with a rod or wire across the top. Drill a hole threw a small flat board. Put that out in the middle with the rod going threw it. Then put peanut butter on all four sides. They will jump out and fall in when it spins on them. Works with mice on a five gallon bucket.

The tree is a ground. You want the squirrel to be a part of the ground and the method is to have wire separated from the tree until the squirrel climbs the tree and the wire touches the tree while the squirrel is touching both. The problem is that the tree may not be an adequate ground to do the job, but I have a client who set up such system and claimed it worked until his wife made him disconnect it when she saw a dead squirrel in the wires.

I don't know if the squirrel didn't get zapped while paws were still on ground or if adequate power is transferred when the tree itself is the ground. The book is you use a deeply pounded in metal stake wired to metal fencing to create the ground.

He used an electric fence charger- not sure what kind. When I've set up systems I've used both chicken wire and hot wire separated with insulators creating 4' tall boxes around each tree. Works fine, but too much work to be a good system for my business.

Gammo makes a pellet rile that is deadly at 50 yards. Squirrel, it's whats for dinner!

Hman - using the tree as a ground doesn't harm the tree?

I haven't noticed damage at the site I saw it done and I also tried a method where it would happen inadvertently and no problem ever occured/

"using the tree as a ground doesn't harm the tree?"

I can't imagine it would. At one time "weed burner" fence chargers were popular. The idea was to make super hot fence chargers with enough volts to burn weeds touching it, thereby avoiding the chore of spraying fence rows for weeds that would ground out the fence. But they really didn't do a very good killing weeds. Trees would be much harder to kill/injure. A lighting bolt can kill a tree but only because it blows it apart and a lightning bolt carries much more energy than an electric fence (by several levels of magnitude).

Safety of electric fence was mentioned as a concern. Electric fences are very safe for people. Occasionally they do kill some wildlife, but almost never a person. I Googled the statistic and found one human death annually worldwide from electric fences. That is an astoundingly low figure when considering amount of electric fencing worldwide. I suspect more people die or are injured worldwide from barbed wire fencing than electric (i.e. tetanus, arteries severed). My brother ran into a barb wire fence when he was a kid. He received 9 stitches in his face as a result.

I also suspect the deaths from electric fences are not from "pulse" type fences, but from continuous flow chargers (where there exists a very very slim possibility that someone would not be able to let go of the fence if they grabbed it.)

Pulse type DC fences can give a painful "bite" and then let go, but that's the worst of it.

I have no direct knowledge of the effect of electricity on a tree, it reminds me of a science experiment I did when I was in elementary school...

I had two plants, each in separate pots. One plant was grown normally. The other plant was grown inside a magnetic field (I basically built a magnet fence around it). All the lighting and watering conditions were the same. The normal plant grew fine. The magnetic plant grew a bit and died.

What does this have to do with electricity... Well, there is a rule in science that says where there is electricity, there is magnetism and where there is magnetism, there is electricity. So, in theory the science experiment mentioned above should have a very similar result if magnetism was replaced with electricity.

Of course, I was probably about 13 years old at the time I did the experiment, so there could have been many errors. So, maybe don't take the results too seriously...

I don't think magnetism would have an effect on the tree, else power companies wouldn't have to trim trees around power lines (which produce much more magnetism than an electric fence).

I've seen branches grow right up through power lines and myself even cleared branches off that were touching the lines.

The only damage I observed from limbs touching power lines was the bark rubbing off from the "see/saw" action of the limb rubbing the line from the wind. Other than that, the limbs were completely healthy.

I started the other thread about squirrel deterrence - and the idea of a fence charger got me to thinking. I work part time on a farm that uses electrified wire to protect young strawberry plants, as deer can wipe out a potential crop PDQ. It was the job of the first person on the scene each morning to turn off the fence. Sometimes, they forgot.... But the 800v from a fence charger is nothing compared to the 10,000v from a neon sign transformer. (I wondered how I got 6 feet away from where I was and why I was now on the floor....) It's only milliamps....

This is doable: I've got some low, ornamental iron fencing I could use to circle the tree, then put little insulators on the top for the wire to the charger side of the circuit. The iron fence is the ground.

Bwahahahah....Revenge is mine! Besides, what could go wrong, eh? ;-)

Cheers

" (I wondered how I got 6 feet away from where I was and why I was now on the floor....) It's only milliamps...."

Yeah generally it's the amp draw that's the big deal. You can get fence chargers that put out 10,000 volts but the amperage is so low there's no risk of bodily harm.

I think there was some confusion earlier in this thread about what is a proper electric fence. It's not about using house wiring to charge a fence, which would be extremely dangerous.

Many people are killed by 120v even though it really doesn't bite you that hard. The problem is that there is enough amperage on a typical 15A house circuit to constrict ones hand around the lead. The person knows they are being electrocuted and is fully aware of what's happening, but they can't let go.

The same current squeezing their hand also makes it extremely difficult for their heart to continue in it's rhythm. After a few moments, the heart stops altogether. The old refrigerators were bad about electrocuting people in this way because they didn't have a case ground (i.e. just a two prong plug). The refrigerator would get old, the motor would start leaking voltage and someone would come to open the metal handled door in bare feet (with perhaps a little spilled water on the floor) and they couldn't let go of the handle.

Electrifying a fence with a house circuit would have the same effect - would be inviting death.

Plants take current densities far beyond what humans or animals can take, with no damage. Yes, some grass gets burned, but keep in mind that the grass blade cross section is easily hundred thousand times smaller than your midsection.

In my opinion, what has worked in one of my gardens is ideal for this. Surround the tree with a fence (say, chicken wire), that is solid enough to withstand a climbing squirrel. at the top, circle with one hot wire. In my case, the hot wire is about 4 inches off the chain link, two inches from the top. It discourages ground hogs, squirrels, and raccoons.

Now the problem of grounding over long distances is very real and in very dry conditions grounding may fail. It is not a problem in the garden described above because the chainlink provides grounding all around the perimeter, and one side of the garden is right next to the garage and the grounding rod. In my other garden, I have seen grounding failures in dry weather, in clay, over distances of 40-70 ft (the wood chips surrounding it may be partially to blame). I solved this, by digging a channel under the perimeter, and burying a grounded naked steel wire all around. Now hot wire and ground are never more than 2 ft apart.

For isolated trees, you would still have to bury a ground wire going to the chicken wire cage. One could save work by digging one channel per tree, carrying a plastic conduit with the hot wire, and the ground wire. My gardens all are fed with high wires (8-9 feet high), from the house or garage, feeding into a vertical PVC pipe planted in the ground just inside of the garden. The wires come down the pipe and exit through holes (hot wire height for hot, ground level for ground). High wires are, of course, a no-no in an orchard, on the other hand there is no tilling in an orchard.

My new orchard is getting a single hot wire around (I am building it right now), which is not enough for total protection (animals can pass under, above, or run through it) and will have to be reconfigured once the trees fruit. The ground is through chicken wire buried all around to prevent digging predators. I might do one digging for drip and wiring once I place my drip system underground in the orchard, but because I have hazelnuts, which have multiple stems, I will probably go with alternated wires all around the perimeter, as Hman suggests.

"Sometimes, they forgot.... But the 800v from a fence charger is nothing compared to the 10,000v from a neon sign transformer. (I wondered how I got 6 feet away from where I was and why I was now on the floor....) It's only milliamps.... "

We used a neon sign transformer for a elctric fence when we had problems with wild hogs tearing up our garden. They would go through a regular electric fence by sending one ahead to break the wire but the neon transformer seemed to work.

Roger that...but I'm surprised that even a 10,000v charge would stop a herd of determined, feral hogs. Usually, you need something a tad more powerful, like a bazooka or an RPG....

Cheers

Electric fencing rarely kill the offending animal. It is just intended to make the animal associate an unpleasant experience with the locale so they will avoid it. When dealing with bears/coyotes one often baits the electric fence with a favorite treat, The animal comes along and eats it off the fence and gets a big shock to the mouth. Somewhat effective in that they avoid the area after that.

You could try the same thing with these rodents, Create a wet ground area, place a favorite food of theirs in an aluminum plate insulated from the ground and on the fence hot line. All near the tree. However you run the risk that you'd be training them to avoid the plate and go for the tree.

Given their ability to jump from tree to tree and ground to tree, an electric fence solution is probably not ideal here. Shooting them, a hungry cat or two, or poison bait would likely work better.

Squirrel won't usually jump a 4' fence according to a guideline I read from Cornell concerning keeping squirrels out of gardens. They will jump 4' sometimes to reach a branch but I haven't seen them go too much higher than this.

Modern electric fence energizers are high voltage/low impedance(low amperage). The one I have charging my livestock fences registers above 10,000 v when I have all the shorts/grounds taken care of - but amperage is very low(under 10?), when there are 'leaks' in the system. Minimal electrocution hazard, but the 'pain potential' is very high.

The OP's proposal of electrified chicken wire around the tree does pose potential for unintended electrocution of animals or people who might accidentally come in contact with it.
And, as others have opined, it's probably not a workable system, from the outset.

Traps, pellet guns, higher-powered firearms if feasible, big bucket-o-death are all better choices.

lucky - my idea is to use one of those modern fence energizers, not hook up the wire directly to the house current.