I've got two hens that have just easily cleared the 4' fence....they cleared it very easily so that I know if they took a notion, they could clear the 6' around our property. Outside that wall they are not safe....cars, dogs, coyotes, hawk, not to mention just getting lost. I can't make the wall higher. The only solution I can think of is to clip their wings. Chicken people -- what is your opinion about clipping wings?