My ducklings are just about 2 weeks old and they've recently started squeaking like crazy every time I'm out of view. They aren't exactly bonded to me and prefer their own kind but every time I check on them they get very excited and come greet me. Then when I leave, they'll make a panicked squeaking noise for a good hour before they calm down again. They stop squeaking the second I come back into the room. Any idea what's going on?