Think about predators - everything: rats, cats, dogs, hawks, mink, snakes, raccoons, foxes, bears, alligators, human thieves etc - depending on where you are. They taste like chicken. Can you predatorize the coop or will you accept a certain rate of loss (be aware that once they know the chickens are there, they’ll be back). And what are you going to do with injured, not dead chickens?

Our run has hardware netting on all sides including the top and under the dirt, and we let them out in the garden to live their best lives when we’re at home. So far this has kept predation down although we have had some curious cats.

Also if you have kids think about whether your chickens are livestock or pets. Ours are pets that lay eggs.