The smallest bird in the world is the Bee Hummingbird or Zunzuncito (Mellisuga helenae). Is has 1.8 g (0.0039 lb) in weight, 5.4 cm (0.17 ft) in length and 7.5 cm (0.24 ft) in wingspan.
The Bee Hummingbird’s nest diameter has only 3 cm (0.09 ft). This species is endemic to dense forests and woodland edges on the main island of Cuba. Interestingly the Bee Hummingbird beating its wings 80 times per second.