My 12 red and black star chicks were hatched on October 27,2008 (almost 11 weeks old) and are housed in a coop with an outside protected yard. On warm and sunny days they look to be agonizing to get out of their yard. When would they be ready to do that and not be a meal for a hawk? Also, how long do I keep them on starter crumbles and can switch to layer mash and scratch. This is our first experience and we are loving our girls!