We had seven - two month old Rhode Island Reds, let them out of the coop in to their fenced run with six foot high chain link and a huge black bird came down attacked one of the hens. It seemed to just want to kill it, didn't try to take off with it or anything. My three boys and I were horrified, being the first chicken we've lost. Will covering the pen with landscaping cloth or something like it keep the "girls" safe or does the pen need to be fenced on the top as well? Do Ravens attack chickens??? Thank you for the help.