If the chickens jump they won’t be able to accidentally touch the zapper? It has to be a really high roof for you to be able to guarantee they won’t. We have a bantam chicken who was able to jump all the way up to the ceiling on our run. The run roof is at least 190cm’s tall. Maybe if you attach it outside of the coop, but that would have a risk of hitting the birds. It most likely wouldn’t kill the chicken, but it does have a risk of severally injuring the chicken. Also if a chicken does manage to hit it and also manages to knock it down how do you stop it from hurting the other chickens as they (being chickens) come and start pecking at it. I know some zappers these days have like a extra layer of none electric wire surrounding the actual electric wire. I personally think it’s not the best idea to put an object that can kill something around your chickens.