I am by no means an expert (I've had my chickens for less than a week) but with the millions of books and internet postings I read prior to getting them, I would say for most of the time they need to be in a covered run and only allowed to free range when you can be there to supervise. But I could be completely wrong on this...After firing off that smarty question in response to yours, I am at a loss as to how to advise you. Any way you can cover the top? I am hoping to see someone with more knowledge than me advise you about what is best. Good luck.