Wing Feathers

Hi everyone The Battery henshave been with us two weeks and all are progressing well. Soon as they see me they are carrying on thinking food is on its way. Soon learnt the art of dustbaths, scratching for bugs and generally enjoying life.
Their feathers are starting to grow back, I want to let them have free run of our field, how long befoire their wings grow back so that if a predator comes calling they can try and get to safety.
The back of our Ark had been attacked by an animal the other evening, gnaw marks into one panel, We re-inforced and put pallets along the back to make it even more difficult for these pesky critters. Any ideas anyone could it be badger of fox?