I have 6 chicks that are about 7 weeks old and 3 hens. The chicks are about 1/3 the size of the hens, I've had the chicks in the coop for Atleast 2 weeks just seprrated from the hens. When can I take the fence down? Or what if I cut a hole in the dividing fence so the chicks can get away from the hens if need be ??