Scarce As Hen’s Teeth
Explanation: If you say something is as is as scarce as hen’s teeth, then you mean it is very difficult or almost impossible to find.
Example: During the Olympics, it is impossible to find a reasonably priced hotel room. They are as scarce as hen’s teeth.
Origin: This phrase is thought to be an Americanism dating back to the colonial period (c. early 1600s.), but the first recording of it doesn’t appear until 1862. The imagery behind this phrase relates to something we probably don’t think about too often: birds don’t have teeth.