If you think about it...their not that much different from ourselves, when presented with the same kind of situation....maybe we as 'humans' don't show it as acutely as animals do but the uncertainty is there and 'we feel it' and show it, too!They are getting there! As for the chickens, well, for critters that hate any kind of change as much as they do, watching them get over that initial uncertainty, get more comfortable, and then BAM! suddenly adapt has always been one of the most interesting parts of observing their behaviors!
How scared are they really? How long will it take them to figure out the new environment? And how long until we look out and see them totally settled and content? Just fascinates me!