I have a half acre fenced in for chickens. Can I let them free range all day and lock them up in their coop at night? I have a 6' fence in most of the yard, but at one part in the yard it's only about 3'. Will they get out? Can I train them to stay in the yard? Will cats or hawks kill them? P.S. My yard is completely coyote proofed because I have dwarf goats. However, cats and small critters can get in.