Definition & Meaning of "(as|) scarce as hens' teeth"

What is the origin of the idiom "scarce as hens' teeth" and when to use it?

The phrase "scarce as hens' teeth" is a colorful idiom that originates from the fact that hens, like most birds, do not have teeth. The absence of teeth in hens makes the comparison to something "scarce as hens' teeth" a vivid way of expressing extreme rarity or scarcity. This expression is used to emphasize the extreme rarity or scarcity of something. It conveys the idea that the item or condition being described is exceptionally hard to find or very uncommon.