Most people do have an open space that the chickens just step over. You certainly don't have to if something else works better for you. The perch is just there to give the hens something to jump/fly up to and then they can step into the nest boxes. I don't even have a perch in front of my nestboxes, my hens just jump/fly up to the nest box it self. I am wanting to add one eventually though, I think having a perch is a nice 'help' for the girls.