"Q" is the only letter in the alphabet not appearing in the name of any U.S. state.
Hawaii is the only U.S. state never to report a temperature of zero degrees F or below.
Hawaii is the only state with one school district.
Koala and humans are the only animals with unique fingerprints.
Seals sleep only one and a half minutes at a time.
The only bird that can swim and not fly is a penguin.
The only continent without reptiles or snakes is Antarctica.
The hummingbird is the only bird that can fly backwards.
Honeybees are the only insects that create a form of food for humans.
The starfish is the only animal that can turn its stomach inside out.