I use hot wire around the outside of my pens and along the top to discourage things like fox and coyote as well as roaming dogs. Barbed wire won't faze them, they'll just slip through or over it with no problem. Any critter that comes sniffing around a hot wired pen is probably going to stick it's nose on that wire at some point, they aren't usually interested in trying it again. And being's that the wire is outside my pens and along the top of the fence line it is out of reach of my birds.