Rare as Hen’s Teeth

Twists & Turns of Phrase

When something is as rare (or scarce) as hen’s teeth, it is very rare to find it, perhaps even impossible.

This phrase first came into use in mid–19th century America, where anyone with a chicken coop could see that birds have beaks, not teeth. Interestingly, though, some researchers at the universities of Manchester and Wisconsin have discovered that hen’s teeth are not nearly so rare as once thought.