All three were pancaked on the far corner behind the vent. Suddenly, all awake and toddling down off screen. Must have been a parent arrive with food. Big Sis (I don't really know, just seemed the biggest one) was back in view with Trey who carried a little something. Sis grabbed, Dad let it go and stood on the ledge at the far corner. She worked and worked, barely visible on the screen, at whatever it was, and Trey gave occasional glances at her before swooping off the ledge. Now both other chicks have come back and are vaguely interested in what Sis is doing.