I have 4 chickens that are 2 months old. I just finished their coop and put them in yesterday. My question is, if I let them free range in my back yard, are they going to get more parasites and require worming, antibiotics, etc? If I keep them in a run, will they still need to be wormed? Also, do you think they will be safe free ranging inside a privacy fence during the day without me being home? Thanks.