Pigeons on the London underground

Pigeons have been travelling on the London Underground since its inception. Photos exist from the early 1920s which show trained pigeons (those seeking to find meaning after their use in World War I) picking up discarded tickets and using them at the gates to enter and exit stations semi-legitimately. One of the popular Pigeon Expresses (as they soon became known known for pigeon commuting) was the Bakerloo service which ran from Regents Park to Trafalgar Square (closed 1999).