B-Side Radio: Dusk

In zoology, crepuscular refers to animals becoming active at twilight or before sunrise, as do bats and certain insects and birds. On this edition of B-Side Tamara Keith and Rene Gutel explore dusk, with a walk on a busy trail. Stories include a visit to the National Zoo, an exploration of "magic hour," and a trip to the top of the empire state building with the man who lights it up.