U.S. Patent # 3,593,345 was granted for the "whisper seat," a toilet seat with soundproof lining to prevent noise from being heard by others.

The honey bee is the only bee that dies after stinging.

The bat is the only mammal that can fly.

Sharks are the only fish that can blink both eyes.

James Buchanan was the only bachelor US President.

Maine is the only state in the US which has one syllable.