A quick peek in at our tree swallows. Mom and dad have been busy hauling food in throughout the day. We've had catbirds and kingbirds perching on what the swallows think is their perch not far from the box. The swallows have been very careful not to leave the nest untended. There's almost always an adult in the box. When one returns, it calls on approach to the box and the one inside heads out. Not sure if that's how swallows always work, or if the outsiders have them keeping a closer eye on the chicks.