Chickies generally do not wonder too far from the coop. They tend to form groups with a rooster in charge. If you notice during the day all the roos will crow and let all the other roos know where exactly they are. I hear this all day long. One will crow, another, then another all pretty much right after the other.
I am guessing this is their survival instinct. It is a rare occurrence that I see a group of birds that are out of visual range of the "coop".
I see them running towards the coop during the day and then when they stop they are with their group or another.
If you sit down and carefully watch them without them really knowing you are there the dynamics of it all makes a lot of sense. They seem to be very aware of where they are and where the rest of the groups are. One by one each group will go to the coop and go in at night.
A few roos will stay out and make sure everyone is in and then retire themselves. If you have more than one roo you will hear them calling their groups in.
I have one roo that seems to be in charge of the entire flock. He is ALWAYS the last one in. He gives a few crows, goes around the buildings and then goes in himself. I recently have noticed that he stays in front of the doorway and will not allow any one to go back out. I thought this was just a coincidence until I saw it every day for days on end.