Welcome to BYC! My recommendations is to use 1/2 inch hardware cloth (very strong mesh wire) instead of chicken wire, and to make sure and bury the wire underground around the run to prevent digging. Here are a couple of forums you may want to look into: https://www.backyardchickens.com/atype/1/Learning_Center and https://www.backyardchickens.com/f/13/predators-and-pests good luck to you!