How are the chickadees like people that Sam knew on Third Avenue in New York?

The chickadees, like the people on Third Avenue, have their favorite routes to and from the best food supplies. They have their own resting perches, and each has a little shelter in the cavity of a tree where they fly at night. They chatter and call good night and make a fuss before they part. Then the forest is as quiet as the apartment house on Third Avenue when all the kids are off the streets and all the parents have gone home