My son built a new chicken run for us which contains 2 coops, one for the venerable ladies and one for the young ones. It's 4x2" welded wire 14 gauge, sides, roof, and extended apron. For the first time I feel the flock is truly secure. You can use netting but that won't stop raccoons and other predators who see the chickens as their tasty treat. We have a pair of hawks who nest annually in our neighbor's tree. For me the limit was when my pullets were about 8 weeks old this summer and one of the young hawks learning to hunt swooped in and landed in the plum tree right beside me. I was yelling and waving my arms (living scarecrow, y'all!) and it looked at me like I was there for entertainment. My son started on the new run a couple of weeks later.