Hello, We are converting our child's playhouse into a chicken coop (for two chickens). The playhouse (4x4) is on stilts and sits atop a 6x4 sandbox which will become the run (teaching our child the meaning of sharing -- or at least giving to the vulnerable). Could we have an entrance through a door on the bottom? Access would be via ramp. How large a hole? Given the run will be very secure is a door necessary? Thanks in advance.