We used the garden variety netting over our two new runs last year. It works for the birds, but we had a bobcat sneaking in one corner. He'd jump on the roof of the adjacent coop, he peeled back the netting in one corner, just enough to slip through, and was helping himself to our birds inside the coop for 3 nights before I saw him one night. I was letting the dog out before bed, looked towards the coops, and saw a gynormous cat just sitting there on the roof. We noticed the missing birds, but not that the netting had been pulled back just slightly. We have since replaced it with chicken wire and so far haven't had him back that we know of.