How far apart should my perches be so that the chickens don't poo on a perch while they're standing on the one in front of or behind it? I'm assuming the spacing would be different for bantams. Should I just measure from the feet to the vent and add a half inch? Trying to figure this out so I can keep the perches as clean as possible. Of course they will step in poo and track it, but preventing pooing ON the perches will minimize the clean-up. Thanks!