Bee Hummingbird: World's smallest bird

Only found in Cuba, these birds lay their eggs in nests the size of a quarter.

From Audubon:

It measures a mere two and a quarter inches long.

Bee Hummingbirds are often mistaken for bees.

They weigh under two grams — less than a dime.

Their wings beat 80 times per second [my italics].

That's half the weight of our backyard hummers, like the Ruby-throated or Rufous.

The female builds a nest barely an inch across.

Her eggs are about the size of a coffee bean.