Our five chickens are just under 7 months old and we are planning on getting another five in the spring. We have just under two acres and the chickens have just started 'migrating' over to a neighbor's yard (we prefer to let the chickens free range during the day). We have decided to put up a picket fence to hopefully keep the chickens in the backyard (they will have almost an acre to roam). My question is: Should we put up a 4 ft. or 6 ft. fence? Any fence suggestions for us? Thanks so much!!!