A Lion at its Watering Hole

As long as I've had the ground level bird bath, I've observed a very interesting relationship involving juvenile American Robins. These youngsters always seem to base themselves close to the bath (and it happens even when I moved the bath some distance), but I never see them use the facility. Is this an instinctive behavior? did pre-suburban Robins cluster close to a water source like lions around an African water hole? do the Robin fledglings feel safer at the bath? Perhaps it is some of both. And as the birds age they're more willing to move farther afield and even use the pedestal bath for feather care. I'm please they like my arrangements!