I had to do something in building something that my ladies will be secure in. I have been using a chain linked fence system in the old coop that was on the property when I moved to it. After a year and a half of no issues, I caught a raccoon killing two of my hens by reaching into the coop. The new building for them has reinforced chicken wire and a better place to nest and roost. I have also put a light out in the pen area at night so I can see inside it from the house.