Took the family on an afternoon hike last Sunday to Knoch Knolls (which is pretty much the best thing I've found in Naperville during the 7 years of living there so far.....mature hardwood forest, Dupage river running thru it, some prairie) and what do I see? A flock of 4-5 Bluebirds doing their happy thing...perching in the treetops and then swooping down to the ground to eat a cricket or something and then swooping back up to join their friends. I've seen a handful of bluebirds before but only singlely, never in a flock like that.