I might add, I live in Southern Maine on 3.5 acres. Here in Maine we have ticks bad, really bad and that was the reason for the chickens in the first place. We were pulling them off the kids and dogs daily, I myself think I got lymes disease (as I had the early signs) and went through the treatment and thankfully caught it early. There is definitely a noticeable drop in the tick population when they are out (not to mention the eggs get better). Putting up a fence would be challenging expensive and come with some liability as the lot line runs weird and any way I go I would have to cross onto other neighbors property to make the fence effective. To me, it boils down to if they aren't your chickens, don't put out a buffet for them. They might not be the smartest animals, but they are smart enough to remember where to get a free meal. I plan to let them out later in the day so they have a couple hours to roam and hopefully they will stick closer to home. The other possibility is to start a new flock that hasn't been programmed with these bad habits. I suggest the only place to feed chickens is in the coop area. Any food outside the coop area, is scavenge only.