Agree with DobieLover - nothing has ever gotten into our pen either and we have foxes, racoons, coyote, skunk, opossum, etc. - they tried but yelped at night and that was it - seems like they only try again when there is a next generation who has to experience the e-fence for themselves once
yes, multiple strands at all entry points (roof line, window line, floor/door) and don't forget to run hot and ground about 3 inches apart to shock a racoon that comes from the top and does not have ground contact with its feet - do need to keep birds away from that when it is on - I ran into it once and it is memorable, shall we say, even for a big critter like me
good grounding rod
I tested the spark with a metal pitch fork with a wooden handle but putting the metal prong across the wires - whoo-whheee! Blue sparks!
The emf may not be good for the birds but I did it for years and they seemed fine - can mount the fencer further away from the coop and run a wire to it if that is a concern, to keep the emf ffrom the fencer down (they will still get some from the wire being close but not as much, I think) - my fencer was right on the other side of the wall from where they roost - oops
here is a picture with some descriptions of our set-up (below)
I used a 50 mile horse fencer and aluminum wire (excellent conductor) and fence post insulators - they actually sparked in places and I had to double up on the insulators (putting one on top of the other before nailing it on and running the wire on the top on, away from the coop that can get wet in the rain)
the nice thing about the horse fencer, rod, wire, insulator combination is that you can make it any shape you want - just keep the wire from touching anything and you can run it around the coop and run and windows and doors, etc. it is firm and stays in place and lasts for years
I made a "gate" across the door with an insulated handle so that I can string the wire across the door when I lock up at night
like I said, wildlife has tried to get in, but learned not to try again - we had a few yelps at night and birds toppled everything over inside overnight due to flight, but nothing got in and no birds have been killed inside the coop so far (7 years)
Now we have the dogs and I got rid of the e-fence so they don't get sparked - hope we stay safe!