We have a flock of 9 that we keep in our back yard. It is a pretty large back yard and it is fenced in 6' high. We have the coop and around the coop we have about a 20x20 area penned off. We rarely pen the chickens up and usually just let them roam around the back yard. We have one hen that continues to hop the fence. She just wants to be in the front yard for some reason. Does anyone have any suggestions on why she is doing this and how to keep her in the back yard besides keeping her penned?