We have a friend who is a retired postal worker. Not a mail carrier, he worked in the mail terminal where everything was sorted to go to the smaller post offices. He worked the night shift. Things would tend to drag come the wee morning hours. The workers would cheer up when a box of peeping chicks would come in. He couldn't explain it but all the workers would perk up! He also told of a time when a box of pullets came in and their box popped open. What a time they had gathering up those girls!