It was kind of funny, when we first opened up the area, the chickens came over and stood at the border of the old area. They kept looking at the new area but nobody was inclined to wander in. Chickens aren't generally the 'leap before you look' type. They like to look and discuss and think about it and discuss it a little more and then, hey, let's think about it some more. Mandelas was the first adventurer in and she just loved it. By the end of the day, most of the chickens had decided that it was worth checking out. They seem to like the old tree at the end of the pen.
The new area easily doubles the area the chickens have. The more space they have, the happier they'll be. They very rarely wander alone, most have a couple they like to pal around with.