I started letting my girls (and the gang of giddy guineas) out in the late afternoon (4:00 ish) about a week ago. The first day or two, we "babysat" them - totally nervous that they'd head south and never be seen again. Obviously, chicks are smarter than their keepers. Though the guineas have a tendency to wander further, they always go in a noisy pack, and they're always the first back into the coop come twilight. The chicks don't wander as far (to date they haven't gone more than 15 or 20 feet from their coop) but they're also the 'night owls' of the bunch, refusing to come in until the light is about gone.
I love watching them free range. They're exquisitely happy, making little chortling sounds as they wade through the brush and grass. Now that they've found their way into one of the horse pens (ahhh, all that BUGGY manure!), they're even happier.
Chickens are such fun. Everyone should have them!
Susan